Which is correct, used to or used to? The answer is the same as for supposed to!
When using the phrase used to do NOT omit the d. Used to is incorrect, ALWAYS.
For Example: Andrew used to write for 20 minutes a day. (It is not correct to write “Andrew use to write for 20 minutes a day.”)
For Example: Jennifer used to take a writing course. (Again, It is not correct to write “Jennifer use to take a writing course”)
This fix is easy to remember: Just keep the d!
Tweetable: Grammar Tip: Used to Vs Use to