PAST SIMPLE TENSE
I watched a film yesterday. - I didn't watch a film yesterday.
We/You/He/She/It/They watched a film yesterday. - We/You/He/She/It/They didn't watch a film yesterday.
Did I watch this film? - Yes, I did. - No, I didn't.
Did we/you/he/she/it/they watch this film? - Yes, we/you/he/she/it/they did. - No, we/you/he/she/it/they didn't.