<Dave a few years ago >_______________<Dave today>
I work in a factory.____________I work in a supermarket. I used to work in a factory.
Dave used to work in a factory. Now he works in a supermarket. Dave used to work in a factory=he worked in a factory in the past,but he doesn'twork there now
You can say I used to work.../she used to have.../they used to be...,etc.
***I/you/we/they (used to ) <be/work/have/play(etc.)>*** ***he/she/it
#, When I was a child,I used to like chocolate.
#, I used to read a lot of books,but I don't read much these days.
#, Liz has short hair now,but it used to be very long.
#, They used to live on the same block as us,so we used to see then ofen,but she sold it when she moved.
(The negative is I didn't use to....) #, When I was a child, I didn7t use to like tomatoes.
(The question is did you use to...?) #, Where did you use to live before you came here?
**We use used to......only for the past. You cannot say"I use to,,,"(present).