Think Verb Forms: Present, Past, and Participle

The verb think is irregular. Its three main forms are: think (present), thought (past), and thought (past participle). Unlike regular verbs that add -ed, think changes its spelling completely. This guide covers every form, common uses, and typical mistakes so you can use think correctly in writing, conversation, and email.

Quick Answer: Think Verb Forms

• Base form (present): think
• Past tense: thought
• Past participle: thought
• Present participle / gerund: thinking
• Third person singular: thinks

All forms except the base and third person singular are the same for every subject: I think, you think, he/she thinks, we think, they think. The past and participle are always thought.

Think in the Present Tense

Use the present tense for current opinions, beliefs, or mental processes. It is common in both formal and informal English.

Examples

• I think this plan will work.
• She thinks the meeting is at 3 p.m.
• They think the movie starts at eight.

In formal writing, think can sound less definite than believe or consider. In conversation, it is the default verb for expressing an opinion.

Think in the Past Tense

The past tense thought is used for completed actions or states in the past. It does not change form for different subjects.

Examples

• I thought you were coming today.
• He thought about the problem for an hour.
• We thought the answer was correct.

In email, I thought is polite for correcting a misunderstanding: I thought the deadline was Friday, but I see it is Monday.

Think as a Past Participle

The past participle thought is used with auxiliary verbs (have, has, had) to form perfect tenses, and in passive constructions.

Examples

• I have thought about your offer.
• She had thought of a solution before the meeting.
• The idea was thought to be impossible.

In formal writing, the past participle appears in passive voice: It is thought that the economy will improve. This is more indirect and objective than active voice.

Comparison Table: Think vs. Other Common Irregular Verbs

Notice that think follows the same pattern as bring, catch, teach, and buy: the past and participle are the same, and they all end in -ought or -aught. This pattern can help you remember the form.

Natural Examples in Context

Here are examples that show how think is used in everyday situations.

Conversation

• What do you think about the new restaurant? – Present, asking for an opinion.
• I thought you were on vacation this week. – Past, expressing a mistaken belief.
• Have you thought about joining the club? – Present perfect, asking about past consideration.

Email and Writing

• I think we should proceed with the project. – Present, direct opinion.
• We had thought of several alternatives before choosing this one. – Past perfect, showing earlier planning.
• It is thought that the policy will change next year. – Passive, formal and impersonal.

Formal vs. Informal Tone

• Informal: I think you should go.
• Formal: It is thought that your attendance would be beneficial.

In formal contexts, think can be replaced with believe, consider, or deem for a more professional tone. However, think itself is not incorrect in most formal writing.

Common Mistakes with Think

Learners often make these errors. Avoid them to sound more natural.

Mistake 1: Using “thinked” instead of “thought”

Incorrect: I thinked about it yesterday.
Correct: I thought about it yesterday.

Think is irregular. Never add -ed.

Mistake 2: Confusing “think” and “thought” in perfect tenses

Incorrect: I have think about it.
Correct: I have thought about it.

Always use the past participle thought after have, has, or had.

Mistake 3: Using “think” for past habitual actions

Incorrect: When I was young, I think about the future a lot.
Correct: When I was young, I thought about the future a lot.

For past habits, use the past tense thought.

Mistake 4: Forgetting the third person -s

Incorrect: He think it is a good idea.
Correct: He thinks it is a good idea.

Add -s for he, she, it in the present tense.

Better Alternatives and When to Use Them

While think is versatile, other verbs can add precision or formality.

• Believe – Stronger conviction. I believe this is the right decision. Use in formal writing or when you want to sound more certain.
• Consider – Suggests careful thought. We are considering your proposal. Good for business emails.
• Assume – Means you accept something as true without proof. I assumed you knew about the change. Useful for clarifying misunderstandings.
• Suppose – Similar to assume but often more tentative. I suppose we could try that. Common in conversation.
• Reckon – Informal, used in some dialects. I reckon it will rain. Avoid in formal writing.

Choose the verb that matches your tone and level of certainty. In most everyday situations, think is perfectly fine.

Mini Practice: Test Your Knowledge

Fill in the blanks with the correct form of think.

1. I ________ about your idea last night.
2. She ________ the exam is easy.
3. They have ________ about moving to a new city.
4. We ________ the movie was boring, but everyone else liked it.

Answers

1. thought
2. thinks
3. thought
4. thought

Frequently Asked Questions

1. Is “think” a regular or irregular verb?

Think is an irregular verb. Its past tense and past participle are thought, not thinked.

2. Can I use “thought” as a noun?

Yes. Thought is also a noun meaning an idea or the process of thinking. For example: I had a sudden thought. The verb and noun are spelled the same but used differently.

3. What is the difference between “think of” and “think about”?

Think of often means to remember or imagine: I can’t think of his name. Think about means to consider: I need to think about your offer. In many contexts they are interchangeable.

4. How do I use “think” in the passive voice?

Use the past participle thought with a form of be. Example: It is thought that the company will expand. This is common in formal and academic writing.

For more help with verb forms, visit our Verb Forms Explained section. If you have questions, see our FAQ page or contact us. To learn about other irregular verbs, check Past Tense Forms and Past Participle Forms. For common errors, see Common Verb Mistakes.