1)Did you work yesterday?
-Yes, I did. /I worked yesterday.
-No, I didn't. /I didn't work yesterday.
2)Didn't she stay with friends last week?
-No, she did. /She stayed with with friends last week
-Yes, she didn't. /She didn't stay with friends last week.
3)Did they like cats?
-Yes, they did. /They liked cats.
-No, they didn't. /They didn't like cats.
4) Didn't you study on Monday?
-No, we did. /We studied on Monday.
-Yes, we didn't. /We didn't study on Monday
5) Did it stop in December