"He is not against us."

Translation: Li ne estas kontraŭ ni.

[Scorpyn]

Should "Li ne kontrauxas nin" be accepted?

[Mutusen]

Yes.

[NotWaje]

Except that this is the prepositions section. Use your prepositions!

[theBarkingSpider]

Same question.

[Kazzieloo]

I translated this as Li ne estas kontraŭ ni, and it was marked wrong. It said the correct answer is Li ne kontraŭas nin.
I've never seen that "as" ending.