1. Did you know? + Where did he go?

=> Did you know where he went?

2. Did you think? + Why was he late?
=> Did you think why he was late?
=> Why did you think he was late?
- I thought he was late because he got up/gotten up late.

3. Did he know? + When did he come?
=> Did he know when she came?

4. Did he guess? When did he come?
=> When did he guess he came?
- He guessed that he came/had come last Sunday.
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Would you check the sentences? Check the usage and tense, please. Thank you.

1. OK

2. The second question and the answer are fine. The first question is rare.

3. OK

4. OK

1. Did you know? + Where did he go?

- The correct sentence would be: "Did you know where he went?" This is a past tense question asking if the person knew the location where another person went.

2. Did you think? + Why was he late?
- There are two possible correct sentences depending on the intended meaning:
a) "Did you think why he was late?" This is a past tense question asking if the person considered the reason for someone being late.
b) "Why did you think he was late?" This is a past tense question asking for the reason the person thought someone was late. Both sentences are correct, but they have slightly different emphasis.

3. Did he know? + When did he come?
- The correct sentence would be: "Did he know when she came?" This is a past tense question asking if he knew the time or date when she arrived.

4. Did he guess? When did he come?
- The correct sentence would be: "When did he guess he came?" This is a past tense question asking for the time or date he made the guess about his own arrival. It is also possible to say: "He guessed that he came/had come last Sunday." In this sentence, "guessed" is in the past tense, and "came/had come" is in the past perfect tense, indicating the action happened before the guessing.