infinitive vs gerund - "Used to" vs "Use to"

1. 
   

   Is use to incorrect because we use present tense if we talk present habit?

   
   


2. 
   

   What is the difference between the two sentences below?

   
   

I am used to GETTING up late in the morning.
I am used to GET up late in the morning.

Please help me to understand.

Answer

"Used to" is a specific idiom meaning 'accustomed to' , and not strictly related to any meaning of 'used'. 'Use to' is incorrect if it is intended to mean the same thing as 'used to' (though it's a common mistake).

'Used to' is an adjective phrase, so "I am used to ..." is present tense, just like "I am happy".

The idiom is followed by a noun or noun phrase: "I am used to animals" or "I am used to running." "getting up late in the morning" is a valid noun phrase, referring to the action itself. "get up late in the morning" is a verb phrase, and so can't be used there.

The sentence "I used to get up late in the morning" (note the absence of 'am') is also valid, and means "In the past I got up late in the morning".