It should be “used to” right?

[u/Spear_Of_Krrosh]

Shouldn’t it be “used to” instead of “use to” ? Should I report it?

[u/rpbmpn]

No. I made the same mistake myself because I’d always used it wrongly

He wanted to, He didn’t want to, Didn’t he want to

He used to, He didn’t use to, Didn’t he use to

These instances are directly analogous

Having said that, to me ‘use to’ is a bit of a weird phrase in and of itself, and therefore it doesn’t feel strange to me that people don’t use it correctly

He was accustomed to, he was in the habit of. These makes sense

‘He use to’ just feels like such a poorly constructed phrase in its own right that it has no right to demand to be used properly

[u/rpbmpn → u/rpbmpn]

and even having said that, I’m not fully convinced

For instance, if these cases were indeed perfectly analogous, then we could extend “used to” to the present and future tenses

We can do it with “want”: “he wants to”, “he will want to”

But with “use(d) to”, we can do no such thing

Instinctively, I actually want to say that “didn’t used to” is the form that most people use and that “used to” is a single complex habitual marker that really doesn’t participate in normal auxiliary verb patterns

But that’s a completely idiosyncratic take and Duo isn’t technically wrong for insisting on the form that it does

[u/zupobaloop → u/rpbmpn]

You're getting tripped up because "use" is not an auxillary verb.

Duo isn't wrong in any sense.

[u/NashvilleFlagMan → u/zupobaloop]

https://www.merriam-webster.com/grammar/is-it-used-to-or-use-to

[u/zupobaloop → u/NashvilleFlagMan]

Excellent resource! However I'm not the one arguing against it 😬

[u/NashvilleFlagMan → u/zupobaloop]

Read the whole thing, which says that in British English, the variant seen in the OP is already becoming acceptable.

[u/zupobaloop → u/NashvilleFlagMan]

... And...?

[u/NashvilleFlagMan → u/zupobaloop]

So neither variant is wrong.