Ing, maybe you mean "used to" and "be/get used to"?
"Used to" is followed by Infinitive and denotes an action which always took place in the past but does not happen any more in the present:
We used to be friends when we were children. (We are not friends any more.)
"To be/get used to" is followed either by a noun or a Jerund (verb + ing) and means "to be / get accustomed to smth / doing smth":
She was used to jogging on cold mornings.
There's a very nice song which can help you to understand and memorise the expression "used to":
The Beauty of the World
I used to see the stars at night.
I used to hear the birds.
I used to feel the warmth of the sun.
I used to smell the springtime flowers.
And sing so happily.
I used to sing a song about the beauty of the world.
It was a long long time ago,
I used to sing a song.
Before the black cloud filled the sky,
I used to sing a song.
I used to sing a song about the beauty of the world.
Did you use to see the stars shining in the night?
Did you use to hear the birds and feel the sun?
Did you use to smell the flowers?
Their colours were so bright.
I used to sing a song about the beauty of the world.