Used to ...

We use used to do to talk about the past. It is not a tense but it is like a tense. It is a special expression. We use the expression used to do for the past only.

Structure of Used to do

The structure is:

	subject	auxiliary did	not	main verb use	infinitive
+	I			used	to do.
-	I	did	not	use	to do.
?	Did	you		use	to do?

Used or use?

• when there is did in the sentence, we say use to (without d)
• when there is no did in the sentence, we say used to (with d)

Use of Used to do

We use the used to do expression to talk about:

• an activity that we did regularly in the past (like a habit)
• a situation that was true in the past

I used to smoke. ////// past present future

Look at these examples.

the past	the present
She used to work in a shop.	Now she works in a bank.
He used to watch a lot of TV.	Now he doesn't watch much TV.
They used to be married.	Now they are divorced.
There used to be a cinema here.	Now there is a supermarket here.
I didn't use to go swimming.	Now I go swimming.
Did you use to smoke?