Didn’t Know or Didn’t Knew? Correction + Example Sentences

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Didn’t Knew or didn’t know? Which is correct?

If you are trying to make the past tense, we pair “didn’t” with the infinitive (base form) of the verb “know.” Therefore, we can say “didn’t know.”

	Affirmative	Negative	Question
Past Tense	I knew	I didn’t (=did not) know	Did you know…?
Present Tense	I know	I don’t (=do not) know	Do you know…?

Didn’t Knew

“Didn’t knew” is grammatically incorrect.

“Didn’t” is the auxiliary verb in the past tense. When forming the past tense, we pair it with the infinitive of the verb “know.”

Didn’t Know

“Didn’t know” is grammatically correct.

It is the past tense due to the change of the auxiliary verb from “don’t” to “didn’t.”

“Didn’t” is short for “did not.”

Don’t Knew 

“Don’t knew” is grammatically incorrect.

“Don’t” is the present tense of the verb “do.”

When forming a negative sentence in the present tense, we pair “don’t” with the infinitive of the verb “know.”

Don’t Know

“Don’t know” is grammatically correct.

It is the present tense due to the change of the auxiliary verb from “didn’t” to “don’t.”

“Don’t” is short for “do not.”

Example Sentences with “Didn’t Know”

I didn’t, you didn’t, he didn’t, she didn’t, it didn’t, we didn’t, they didn’t.

• “I didn’t know that he was deaf until I saw him using sign language.”
• “I didn’t know you were such a good singer!”
• “We didn’t know why he quit his job.”
• “They didn’t know how to use the new software.”
• “I didn’t know you liked classical music.”
• “He said he didn’t know anything about the robbery.”
• “I didn’t know how to fix my computer, so I gave it to the repair shop.”
• “We didn’t know she was married.”
• “I didn’t know you were going to be here today.”
• “You didn’t know I was joking!”
• “Didn’t you know that smoking is bad for your health?”

Example Sentences with “Don’t Know”

I don’t, you don’t, he doesn’t, she doesn’t, it doesn’t, we don’t, they don’t.

• “I don’t know how to make a cake.”
• “I don’t know where he is.”
• “She doesn’t know how to do her taxes.”
• “He doesn’t know which job he wants to apply for.”
• They don’t know what the future holds for them.
• We don’t know if the company will be able to recover from this.
• “Don’t know why but I just can’t concentrate today.”
• “I don’t know what’s going on with her lately.”
• “We don’t know how to respond to that situation.”
• “He doesn’t know how to get out of this mess.”

Quiz

Test your knowledge with these gap-fill exercises! Choose the correct word to complete each sentence.

1. I ________ you were going to be here today.

A) didn’t knew

B) didn’t know

C) don’t knew

D) don’t know

2. They ________ how to use the new software.

A) didn’t knew

B) didn’t know

C) don’t knew

D) don’t know

3. “She ________ that smoking is bad for her health.

A) doesn’t knew

B) doesn’t know

C) didn’t knew

D) didn’t know

4. We ________ she was married.

A) didn’t knew

B) didn’t know

C) don’t knew

D) don’t know

5. “I ________ how to fix my computer, so I gave it to the repair shop.”

A) didn’t knew

B) didn’t know

C) don’t knew

D) don’t know

6. He ________ which job he wants to apply for.

A) doesn’t knew

B) doesn’t know

C) don’t knew

D) don’t know

7. They ________ how to respond to that situation.

A) didn’t knew

B) didn’t know

C) don’t knew

D) don’t know

8. I ________ what is happening.

A) don’t knew

B) don’t know

C) didn’t knew

D) didn’t know

Answers:

1. B) didn’t know

2. D) or B) don’t know or didn’t know

3. B) doesn’t know

4. B) didn’t know

5. B) didn’t know

6. B) doesn’t know

7. B) or D) didn’t know or don’t know

8. B) don’t know

Bottom line:

The phrase “didn’t know” is in the past tense, while the words “don’t know” are in the present tense. For the past tense, we use “didn’t,” and for the present tense, we use “don’t.”

“Didn’t knew” and “don’t knew” are incorrect.

Can you make a sentence with “didn’t know?” or “don’t know?” Be sure to let me know in the comments below!

Useful Links

• Is It “Have” Or “Has?” (Examples & Quiz)
• Thier, Their, There, They’re: Simple English Correction
• Putted or Put? Which is Correct?
• What’s Their Name or What Are Their Names? Which is Correct?
• No Worry, No Worries or Don’t Worries: Which is Correct?