Think Verb Forms: Present, Past, and Participle

The verb think is irregular, meaning its past tense and past participle forms do not follow the standard -ed pattern. The three core forms are think (present/base), thought (past tense), and thought (past participle). This guide explains exactly how to use each form correctly in business emails, everyday conversation, and formal writing, with clear examples and common pitfalls to avoid.

Quick Answer: Think Verb Forms

Present Tense Forms of Think

The present tense of think is used for current opinions, beliefs, or ongoing mental processes. In the third person singular (he, she, it), it becomes thinks.

• I think the deadline is reasonable.
• She thinks the client will agree.
• We think this approach saves time.

In informal conversation, think often softens statements: I think we should wait sounds less direct than We should wait. In formal emails, it still works but can be replaced with believe or consider for a more professional tone.

Past Tense: Thought

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

• I thought the meeting was at 2 PM.
• They thought the budget was approved.
• She thought about the issue for hours.

In business emails, thought can express a past opinion that may have changed: I thought the report was complete, but I see it needs more work. In conversation, it often introduces a reflection: I thought you knew about the change.

Past Participle: Thought

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

• We have thought about your suggestion.
• She had thought of that solution before.
• The plan was thought through carefully.

In formal writing, the past participle often appears in phrases like well-thought-out or thought-provoking. In emails, it helps show completed consideration: We have thought about your request and will respond soon.

Present Participle / Gerund: Thinking

The -ing form thinking is used for ongoing actions or as a noun (gerund).

• I am thinking about the proposal now.
• Thinking creatively is important in this role.
• They were thinking of a different approach.

In conversation, I am thinking sounds more tentative than I think. In emails, I am thinking can signal that a decision is not final: I am thinking we should delay the launch.

Comparison Table: Think Forms in Context

Natural Examples of Think in Use

• Email context: “I think the revised timeline works. I have thought about the risks, and I believe we can proceed.”
• Meeting context: “She thought the presentation was clear. We are thinking about the next steps now.”
• Everyday conversation: “I thought you said 3 PM. I think I misheard.”
• Written report: “The team has thought carefully about the budget. This plan is well thought out.”

Common Mistakes with Think

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

Some learners incorrectly add -ed to form the past tense. The correct form is always thought.

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

Mistake 2: Confusing past tense and past participle

Both forms are thought, but they are used differently. The past participle needs an auxiliary verb.

Incorrect: I thought about it already. (when meaning present perfect)
Correct: I have thought about it already.

Mistake 3: Using “think” for past habitual actions

For repeated past actions, use thought or used to think.

Incorrect: I think that was the best option back then.
Correct: I thought that was the best option back then.

Mistake 4: Overusing “think” in formal writing

In formal business writing, think can sound too casual. Consider alternatives like believe, consider, or view.

Too casual: We think the proposal is strong.
More formal: We believe the proposal is strong.

Better Alternatives to Think

Depending on context, these alternatives can add precision or formality:

• Believe – stronger conviction: I believe this is the right decision.
• Consider – careful evaluation: We consider this option viable.
• Assume – taking something for granted: I assume the report is ready.
• Suppose – tentative opinion: I suppose we could try that.
• Reflect – deep thought: She reflected on the feedback.

Use think for everyday opinions and believe or consider for formal or professional contexts.

Mini Practice: Think Verb Forms

Complete each sentence with the correct form of think.

1. I ________ about your proposal yesterday.
2. She ________ the meeting starts at 10 AM.
3. They have ________ about the risks carefully.
4. We are ________ of a new approach.

Answers: 1. thought, 2. thinks, 3. thought, 4. thinking

Frequently Asked Questions

Is “think” a regular or irregular verb?

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

Can “thought” be used as a noun?

Yes, thought can be a noun meaning an idea or the process of thinking. For example: That is an interesting thought. This is different from the verb form.

What is the difference between “I think” and “I am thinking”?

I think expresses a general opinion or belief. I am thinking suggests an ongoing process or a tentative idea. For example: I think this is correct (firm opinion) vs. I am thinking about the problem (current activity).

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

Use the past participle thought with a form of be. For example: It is thought that the project will finish early. This is common in formal or academic writing.

For more on verb forms, visit our Verb Forms Explained section. If you have questions, see our FAQ or contact us. For common errors, check Common Verb Mistakes. Learn about past forms at Past Tense Forms and Past Participle Forms.