I got this wrong -- He hasn't been anywhere yet -- because I left out "vůbec." But where is "ještě" in the correct translation above?
When I got it wrong, it was because I didn't include "at all" in the translation. "Yet" is definitely accepted, so perhaps there was something else in your sentence that Duo didn't like. For troubleshooting, it's helpful if you use the Report button, because then we can see your complete answer.
How necessary? This is a translation from Czech to English. Without ještě it is a different sentence.
ok. but if jeste means yet and the given answer doesn't have it.. What roll does jeste play? vubec means at all nebyl - he hasn't been nikde anywhere ?
We often assume that the present perfect tense already contains the už/ještě information. But we do accept "still" or "yet" here and in the other direction we do accept sentences without "ještě".
So in this sense "ještě" is indeed not necessary.
Why is this 'has been' and not 'was'? It is (default) imperfective, right? Also, 'been' suggests a verb of motion in this context. (Where did he go today? He has not been anywhere at all.) I am a bit slow picking this up. (I think of the past imperfect in french and italian. Equals present perfect in english??)