Listen when we always want to talk or say something which is in the past If we use "did"or "didn't" or "did not" the verb after this one will be in the infinitive or present ok ex: "Last week I didn't go to school" Ok so hope you understood

I didn't see the message is correct. This is confusing because it happened in the past and makes you think you need to use "saw", as the past tense. However, the past is applied to "to do" not "to see" in these negative statements. "See" in this case is actually a bare infinitive (an infinitive missing the "to" part). That why you have: - I did not (past) see (infinitive) the message. It's the same in the present: - I see the message - He sees the message - He does not see the message (not he does not sees the message)

the second one

I didn’t see your message Or I didn’t see the message Which one is correct?

The last one