"His great-grandfather looked sick."
Translation:Lia praavo aspektis malsana.
I know this is an old question, and this kind of thing appears in other sentences, but I'll re-explain it as other people have.
Essentially, this sentence is short for "Lia praavo aspektis esti malsana" In which case the adjective wouldn't be in the accusative case, because of the verb "esti".
should "malsana" be adverbial here "malsane" similar to: "ĝi gustas bone" "li aspektas malsane" this is a confusing grammatical point for me
So, aspekti is okay but sxajni isn't, which leads me to wonder if anyone can help me understand the distinction between these two verbs?