• USED TO
Choose “used to” to say that something existed or happened repeatedly in the past but does not exist or happen now.
For example, “I used to eat pancakes.” That means I ate them repeatedly in the past but do not anymore.
The sentence structure is: subject + used to + base verb
The negative of “used to” is “did not use to” or the more common “didn’t use to.” Notice the word “use” does not end with the letter -d in the negative.
That is because “did” is already the past tense.
• BE USED TO
Choose “be used to” to say you are accustomed to something, and so it seems normal or usual. If you are used to something, it is not difficult, new or strange.
The sentence structure is: subject + be + used to + gerund, noun or pronoun.
For example: "I've been going to this class for a year now. So I am used to waking at sunrise".
• GET USED TO
This phrase is related in meaning to “be used to.” The difference is that “get used to” means someone is, was or will become accustomed to something.
The sentence structure is: subject + get + used to + gerund, noun or pronoun
For example, “She is getting used to the early hours.” That means she is becoming accustomed to being awake in the early morning.