Be used to
Be used to something
Be used to is an expression. It is not a tense. If I say "I am used to Thailand", it is like saying "I am accustomed to Thailand."
Do not confuse be used to with with the special construction used to do. They have different meanings.
Structure of Be used to
The structure is:
subject + be + used to + object
If the object involves a verb, we use the -ing form:
Why do we use -ing for a verb after be used to? Because we always use -ing for a verb after a preposition - and the to is a preposition.
Use of Be used to
The be used to expression is for talking about something that is familiar to us or easy for us. For example:
It means that it is not a problem for me to drive on the left of the road. I am Japanese. In Japan, people drive on the left. Now I am living in the USA where people drive on the right. Of course, I drive on the right in the USA, but when I go to Japan it is easy for me to drive on the left because "I am used to it".
Look at these examples.
We can use be used to in any tense. We just conjugate the verb be in the tense that we need. Look at these examples: