constant Should be constammant to follow the rule: ant = ammant, not amment

Question

Why is this marked wrong?? Constant ends in ant:Bernard travaille ________.Bernard works constantly.(HINT:
French "constant" = English "constant")This was the correct answer: constamment

My
     answer was marked incorrect: constammant, but WHY: constant ens in ant = should be constammant Thanks

Maarten Kamp · Answer

Laura,

I have also just answered on the other section where you posed this question.

The relevant words ending in ‘-ant’ do not go to ‘ ammant‘, as you indicate you wrote. They go to ‘ -amment ‘, as is marked correctly.

https://www.wordreference.com/fren/constamment

This is what I wrote in a previous response on that site, without having added highlighting unfortunately.

And from the lesson :

When turned into adverbs, adjectives ending in -ant and -ent act as follows:

-ant becomes -amment
-ent becomes -emment

Forming adverbs from adjectives ending in -ant and -ent in French (French Adverbs)