Unless, of course, Dutch also uses the singular as English does but here the plural was intended and so needs to be translated as such.
Agree. There's a difference between saying he's appearing passive about a particular situation "shows no emotion", or never shows any feelings about anything "shows no emotions"
Edit: some examples...
"As the verdict was read out, the defendant showed no emotion."
"He is scared to let his guard down, and shows no emotions."
It's not exactly interchangeable. I'd say there are cases where a person doesn't show one specific emotion, and situations where the person doesn't show emotions in general.
.. in which case you would still use the idiomatic "no emotion". Regardless, the Dutch expression, also, is "toont geen emotie".
@Ralvinski - That's the opposite of what this sentence says though. What do you mean by that?
"emotie" ends with an "-e", so it doesn't get an apostrophe in the plural. Words ending in the other vowels do get an apostrophe before "-s".
Hoomalimali is a word. Muumuu is also a word. And hippopotomonstrosesquipedaliophobia, and koramoya, and knaidel are all words in English too. I forgot to mention pffefernuss, schnecka, and weissnichtwo. Three more: Croesus, Backstein, and eponymic.