"Je vois que la fatigue s'installe."

Translation: I see that the fatigue is setting in.

[le-petit-singe]

"... the fatigue" is slightly unnatural English. Just 'fatigue' would be better (but of course it is not accepted).

[CommeuneTexane]

Yes. It helps to have the article "the" for the reverse translation, but it is more natural to say simply "fatigue." That answer is now accepted too. Thanks!

[KevanSF]

The most natural English: "I see fatigue is setting in" is not accepted...

[Vereschagin]

It's annoying when there is not option to submit that my answer is correct. "I see that fatigue is settling in" did not contain a typo and should be a totally accepted answer.

[ALLintolearning3]

Try reporting it. There are so many variations and “I see fatigue is setting in.” was already accepted as correct.

[ian116730]

was accepted today 27nov18

[RQZ.Sash]

Is "the fatigue settles in" (or settles down) not correct? I'm not sure if I need to make it a progressive tense.

[ALLintolearning3]

“Settles down” would not be correct as it means something else.