"Il ne peut que regarder."

Translation: He can only watch.

[samer.sati]

This construction: 'Subject+ne .....que' cannot be translated into negative in English.

For example: je n'aime pas que toi = I love no one but you, or I only live you.

Je ne fais rien que admirer les étoiles= I do nothing but admiring the stars= I only admire the stars.

Notice that we are not using 'pas' after 'ne' the negative.

ne........que

I hope that helps.

[CJ.Dennis]

Actually, "but" is negative, and that's my preferred way of translating "ne ... que" to retain some sense of the French. It's difficult to see how "He can only watch" could use "but", however.

[pfeil]

I'm not a native english speaker, so why is "He can just watch." not accepted as translation?

[maverickpl]

That seems like a perfectly valid answer to me.

[Frenchfried1972r]

Why can't the answer be: "I can't but look" also work?

[ben.kavanagh]

I agree. it seems the most natural tranlslation

[sgb4914]

Is this an idiom? I don't recall being taught ne que. Does it mean "only" like ne pas means "not"

[mmil094]

it's more of a restrictive clause: which can be translated into many other forms aside from only, such as : He can do nothing but watch, I'd also argue He can just watch should work, He can only watch ... etc...

[Koolkaren]

Bingo :)

[BashP]

I think it's helpful to think of the ne .. que construction to mean only or just so Il ne peut que translates to He can only.

https://forum.duolingo.com/comment/27888905

[flyings0lo]

I think "He can only look on" should be accepted.