Have you ever stopped mid-sentence and wondered whether to say “either of them is or are”? This dilemma is one of the most common subject-verb agreement questions in the English language. You might write a business email and hesitate before choosing between “Either of them is fine” and “Either of them are fine.”

Understanding the difference between formal grammar rules and everyday casual speech helps clear up this confusion instantly. In standard formal English, “either of them is” is the correct choice because the word “either” acts as a singular pronoun. However, spoken conversational English often uses “are” due to a natural speech pattern called proximity agreement.

In this comprehensive guide, we will break down the grammar rule, provide clear step-by-step explanations, outline useful shortcuts, and share over 75 practical examples covering business, academic, daily speech, and ESL contexts.

The Quick Answer: Is or Are?

If you need a fast answer for formal writing, academic papers, or business emails:

• Formal / Written English: “Either of them is…” (Singular verb)
• Informal / Spoken English: “Either of them are…” (Plural verb – common in casual conversation, but technically incorrect in standard grammar)

Formula (Formal Standard English):
Either + of + Plural Object Pronoun (them/us/you) + Singular Verb (is/was/has/does)

Quick Comparison Table

Why Is This Grammar Rule Confusing?

The confusion comes down to a structural trap in English grammar: the prepositional phrase.

Consider the clause: “Either of them…”

1. The Subject: The word “Either” is an indefinite pronoun that refers to one item or one person out of two option choices. Because it refers to one, it is grammatically singular.
2. The Object of the Preposition: The phrase “of them” contains the plural pronoun “them.”

When you write or speak quickly, your brain looks at the word immediately preceding the verb—which is “them.” Because “them” sounds plural, your brain naturally wants to follow it with the plural verb “are.”

This grammatical illusion is known as the Rule of Proximity (or proximity agreement). However, prepositions do not determine the subject of a sentence. “Either” remains the true subject, requiring the singular verb “is.”

Step-by-Step Guide to Getting It Right

To ensure subject-verb agreement every time, follow these four simple steps:

Step 1: Locate the verb phrase in your sentence.
Step 2: Identify the prepositional phrase (e.g., "of them", "of the candidates").
Step 3: Temporarily remove the prepositional phrase.
Step 4: Match the true subject ("Either") with the correct singular verb.

Step-by-Step Example

• Original Sentence: Either of them (is / are) suitable for the job.
• Step 1 (Isolate Prepositional Phrase): Cross out “of them”.
• Step 2 (Evaluate Remaining Sentence): Either _____ suitable for the job.
• Step 3 (Substitute “Either” with “One”): One [is] suitable for the job.
• Correct Final Formal Sentence: Either of them is suitable for the job.

Comprehensive Examples (75+ Original Examples)

To build strong context and mastery, review these practical examples categorized by usage context.

1. Basic Examples (Singular Rule Focus)

1. Correct: Either of them is fine with me.
2. Incorrect: Either of them are fine with me.
3. Correct: Either of them has the key to the main door.
4. Incorrect: Either of them have the key to the main door.
5. Correct: Either of them was ready to take the call.
6. Incorrect: Either of them were ready to take the call.
7. Correct: Either of them is capable of leading the team.
8. Correct: Either of them works well in this scenario.
9. Correct: Either of them seems like a viable choice.
10. Correct: Either of them belongs in this folder.

2. Intermediate Examples (Expanding Context)

11. Correct: Either of them is willing to cover the late shift tonight.
12. Correct: Either of them provides sufficient evidence for the case.
13. Correct: Either of them is going to present at the seminar.
14. Correct: Either of them holds the necessary credentials for approval.
15. Correct: Either of them meets our quality standards.
16. Correct: Either of them is scheduled for an interview tomorrow.
17. Correct: Either of them was chosen to represent the regional office.
18. Correct: Either of them is capable of handling delicate customer issues.
19. Correct: Either of them costs less than the original budget estimate.
20. Correct: Either of them is acceptable under current guidelines.

3. Advanced & Complex Sentence Structure

21. Correct: Either of them is expected to deliver the keynote address despite short notice.
22. Correct: Although both designs look promising, either of them is sufficient to launch the campaign.
23. Correct: Before proceeding with the contract, ensure that either of them is fully authorized to sign.
24. Correct: Whether we choose Option A or Option B, either of them leads to sustainable long-term growth.
25. Correct: Either of them is likely to receive the promotion based on recent performance metrics.
26. Correct: After examining both software solutions, the board decided that either of them is compatible with our network.
27. Correct: Neither candidate was flawless, but either of them is better than leaving the position vacant.
28. Correct: Regardless of international shipping delays, either of them is set to arrive by Friday.
29. Correct: Given their extensive research background, either of them is qualified to peer-review the journal entry.
30. Correct: The audit revealed that either of them is capable of managing the institutional account securely.

4. Business & Professional Writing Examples

In professional communication, precision shows attention to detail. Stick strictly to singular verbs when writing formal reports, proposals, and policies.

31. Correct: Either of them is eligible for the annual performance bonus.
32. Correct: Please check whether either of them has completed the compliance training module.
33. Correct: Either of them is competent to manage project deadlines effectively.
34. Correct: The department head stated that either of them is cleared to handle sensitive data.
35. Correct: Either of them represents a sound investment strategy for the firm.

5. Workplace & Professional Email Examples

When writing emails to management, clients, or partners, use singular verbs to maintain a crisp, professional tone.

Subject: Meeting Confirmation - Finalizing Agenda
Hi Sarah,

Thanks for submitting the revised project proposals. 

I reviewed both drafts yesterday afternoon. Either of them is completely fine to share with the executive board during tomorrow's call. 

Please let me know which version you prefer to present.

Best regards,
Mark

36. Email Example: Either of them works for my calendar on Thursday afternoon.
37. Email Example: If you need assistance with the software integration, either of them is available to assist.
38. Email Example: Please let me know if either of them requires additional documentation.
39. Email Example: Either of them is fine for the meeting venue—pick whichever is closer to your office.
40. Email Example: I checked the project timelines, and either of them meets our quarterly deadline.
41. Email Example: Either of them is ready to be sent to the publisher.
42. Email Example: Regarding the client complaints, either of them is handling regional support this week.
43. Email Example: Either of them has the updated access codes for the cloud database.
44. Email Example: Let me know if either of them is interested in attending the tech summit.
45. Email Example: Either of them is free to jump on a quick discovery call today.

6. Academic Writing Examples

Standardized tests (SAT, ACT, IELTS, TOEFL, GRE) and university style guides (APA, MLA, Chicago) strictly enforce the formal rule.

46. Academic Context: Either of them is sufficient to support the initial hypothesis.
47. Academic Context: The study demonstrates that either of them produces consistent chemical reactions.
48. Academic Context: Either of them is valid under contemporary legal precedent.
49. Academic Context: Historical analysis suggests that either of them was responsible for negotiating the treaty.
50. Academic Context: In quantitative research, either of them serves as an effective control variable.
51. Academic Context: Either of them is cited frequently in peer-reviewed literature.
52. Academic Context: The professor noted that either of them is acceptable for the final thesis topic.
53. Academic Context: Either of them exhibits the structural traits typical of modern architecture.
54. Academic Context: From an economical standpoint, either of them is viable for municipal development.
55. Academic Context: Either of them demonstrates a strong correlation with long-term student retention.

7. Daily Conversation Examples (Formal vs. Informal)

In casual conversation, native speakers often use plural verbs without realizing it. Here is how casual speech compares to correct formal grammar:

56. Casual/Informal: “Either of them are fine to pick up dinner.”
    • Formal Standard: “Either of them is fine to pick up dinner.”
57. Casual/Informal: “Do you know if either of them are coming to the party?”
    • Formal Standard: “Do you know if either of them is coming to the party?”
58. Casual/Informal: “Either of them are okay for me to watch tonight.”
    • Formal Standard: “Either of them is okay for me to watch tonight.”
59. Casual/Informal: “Either of them have lived here long enough to know the streets.”
    • Formal Standard: “Either of them has lived here long enough to know the streets.”
60. Casual/Informal: “I think either of them are free right now.”
    • Formal Standard: “I think either of them is free right now.”

8. Student & ESL Learner Focused Examples

For students learning English as a second language (ESL), master this pattern by recognizing that “either” always means “one of two.”

61. Student Example: Either of them is ready to start the lesson. (Meaning: One student is ready, or the other student is ready.)
62. Student Example: Either of them has a red pen you can borrow.
63. Student Example: Either of them is correct in this math exercise.
64. Student Example: Either of them is sitting near the front of the classroom.
65. Student Example: Either of them plays soccer on the school team.
66. Student Example: Either of them is willing to answer the teacher’s question.
67. Student Example: Either of them wants to join the science club.
68. Student Example: Either of them is studying for the final exam.
69. Student Example: Either of them knows how to solve this grammar question.
70. Student Example: Either of them is clean and ready to use.

9. Common Mistakes & Corrections

Below are typical errors involving singular/plural confusion with “either.”

71. Correction: Incorrect: Either of them are going to win the prize. $\rightarrow$ Correct: Either of them is going to win the prize.
72. Correction: Incorrect: Are either of them available for a call? $\rightarrow$ Correct: Is either of them available for a call?
73. Correction: Incorrect: Either of them look good on you. $\rightarrow$ Correct: Either of them looks good on you.
74. Correction: Incorrect: Either of them fit the budget constraints. $\rightarrow$ Correct: Either of them fits the budget constraints.
75. Correction: Incorrect: Either of them have signed the agreement. $\rightarrow$ Correct: Either of them has signed the agreement.

Simple Memory Tricks to Get It Right

Use these simple memory aids whenever you feel stuck:

Trick 1: The “One” Substitution Method

Whenever you see “Either of them,” replace the phrase in your mind with the word “One.”

• Sentence: Either of them (is / are) coming.
• Mental Test: One is coming. (Correct)
• Mental Test: One are coming. (Incorrect)
• Result: Either of them is coming.

Trick 2: Cover Up the Preposition

Use your hand or cursor to physically cover the prepositional phrase “of them.”

• Original: Either of them [is / are] ready.
• Covered: Either is ready.
• Result: The subject-verb agreement becomes clear immediately.

===================================================================
                  GRAMMAR QUICK-REF SHEET
               "Either of Them Is vs. Either of Them Are"
===================================================================

RULE:
In standard formal English (Business, Academic, Tests), "EITHER" is 
a singular indefinite pronoun. It requires a singular verb.

FORMULA:
  Either + of them + [SINGULAR VERB]
  
EXAMPLES:
  - Either of them IS acceptable.      (NOT: are acceptable)
  - Either of them HAS arrived.         (NOT: have arrived)
  - Either of them WAS chosen.          (NOT: were chosen)

INFORMAL EXCEPTION:
  In spoken English, plural verbs ("are", "have") are common due 
  to proximity to "them," but should be avoided in writing.

MEMORY TRICK:
  Replace "Either of them" with "ONE". 
  If "One is..." works, use "Either of them is..."
===================================================================

Practice Exercises

Choose the correct option inside the parentheses according to standard formal English rules.

1. Either of them (is / are) welcome to join our strategy session.
2. (Is / Are) either of them planning to present the report?
3. Either of them (has / have) the experience needed for this role.
4. I checked both files, and either of them (works / work) for the presentation.
5. Either of them (was / were) present during the incident.
6. Check if either of them (is / are) available for a short phone call.
7. Either of them (knows / know) how to process this invoice.
8. Either of them (is / are) a great choice for employee of the month.
9. Either of them (seems / seem) reasonable given the circumstances.
10. Either of them (has / have) submitted the project proposal.

5-Question Quiz

Test your knowledge with these formal English test-style questions.

Question 1

Which of the following sentences follows standard formal grammar guidelines?

• A) Either of them are willing to help us move tomorrow.
• B) Either of them is willing to help us move tomorrow.
• C) Either of them were willing to help us move tomorrow.
• D) Either of them have been willing to help us move tomorrow.

Question 2

Fill in the blank for an executive corporate report:
“After careful evaluation of both proposed software platforms, the IT team concluded that either of them ______ ready for enterprise deployment.”

• A) are
• B) serve
• C) is
• D) feel

Question 3

Identify the error in this sentence:
“Are either of them prepared to take over the manager’s duties while she is on leave?”

• A) “Are” should be changed to “Is”
• B) “them” should be changed to “they”
• C) “prepared” should be changed to “prepares”
• D) No error in standard formal writing.

Question 4

Why does “either of them” take a singular verb in formal writing?

• A) Because “them” is a singular pronoun.
• B) Because “either” is an indefinite singular pronoun acting as the true subject.
• C) Because prepositional phrases always require singular verbs.
• D) It doesn’t; it always takes a plural verb.

Question 5

Which sentence is correct for academic submission?

• A) Either of the theories have been proven incorrect.
• B) Either of the theories are proven incorrect.
• C) Either of the theories is proven incorrect.
• D) Either of the theories were proven incorrect.

Answer Key & Explanations

1. B — Either of them is willing… (“Either” is singular; requires singular verb “is”.)
2. C — …either of them is ready… (Formal corporate reports strictly follow singular subject-verb agreement.)
3. A — “Is” should replace “Are”. (The inverted subject is still “either”: Is either of them prepared…?)
4. B — “Either” acts as the true singular subject of the clause.
5. C — Either of the theories is proven… (Same rule applies when “them” is replaced by a plural noun phrase like “the theories”.)

Frequently Asked Questions (FAQs)

1. Can I ever use “either of them are” in writing?

You can use “either of them are” in informal writing, creative fiction dialogue, or casual online text messages. However, in business communications, academic papers, and standardized exams (SAT, ACT, IELTS, GRE), always use “either of them is.”

2. Does the rule change for “Neither of them”?

No. “Neither” follows the exact same subject-verb agreement rule as “either.” In formal writing, use “Neither of them is…” (meaning not one of them is).

• Formal: Neither of them is available.
• Informal: Neither of them are available.

3. What happens when using “Either… or”?

When using the correlative conjunction “Either… or”, the verb agrees with the subject closest to the verb.

• Example 1: Either the manager or the employees are responsible. (Plural subject closest to verb $\rightarrow$ plural verb)
• Example 2: Either the employees or the manager is responsible. (Singular subject closest to verb $\rightarrow$ singular verb)

4. Why do native English speakers constantly say “either of them are”?

Native speakers often rely on spoken rhythm and proximity. Because the plural pronoun “them” lands right next to the verb position, spoken English defaults to “are.” While common in spoken dialects, it remains non-standard in written English.

5. Does this rule apply to “Either of us” and “Either of you”?

Yes. The rule applies across all object pronouns (them, us, you).

• Formal: Either of us is ready to assist.
• Formal: Either of you is welcome to come.

Conclusion

The debate over “either of them is or are” boils down to formal standards versus casual spoken habits:

• Use “Either of them IS” for formal writing, business correspondence, tests, and professional environments.
• Keep in mind that “Either of them ARE” appears regularly in casual conversation, though it is non-standard.

By training yourself to identify “either” as the true singular subject of the sentence, you can write with confidence and accuracy.

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Disclaimer

This article provides educational guidance based on standard English grammar conventions (including US and UK formal writing standards). While descriptive linguistics recognizes casual spoken variations, the guidelines presented here reflect standard prescriptive writing requirements for professional and academic contexts.

Also read: Each vs Every: Key Differences, Rules, and Examples

Little vs A Little Difference with Examples: The Ultimate Grammar Guide

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