I think the 들 is used more for a group when nothing else specifies plurality. Like "My friends and I eat together". You would say 네 진구들이 같이 먹어요. In this case the number already shows plural.
Yeah they don't use plurals, unless the meaning being assumed as singular would significantly change the meaning of your statement.
Do they buy 30 each or do they all buy a total of 30? This is vague in English. Is it vague in Korean?
Whenever you're specifying a number of long things; pencils, rulers, yarn, and if I recall correctly lengths of time all get this counter, as some examples.
Whoo what a long sentence! Anybody got any tips for retaining long Korean sentences in the brain?
Yeah, writing them down actually is pretty useful for remembering things! Or at least it has been for me. :)
Don't remember it lol just hear it a few times and let it make sense in your brain. All these subject and object counts have a logical structure in Korean so you just need to be one with the grammar. Apart from the counters this sentence really just has a simple subject-object-verb structure which I'm sure is nothing new at this point. Practice coming up with and speaking new similar sentences instead, that'll hammer the essential skills.
I put “Twenty pupils buy thirty pencils” and it called this wrong — even though tapping the word “haksaeng” for the translation reveals that “pupil” is there alongside its synonym “student.” How can I know which synonym Duolingo will accept?
It seems like it's hard to tell sometimes, as it will sometimes accept one answer one time and one another.
Is it necessary to put these counters behind every unit...like , can't we use any common term?
Chinese and Japanese do the same thing. But I'm sure it's easy enough to pick up with practise, like how in English we have slices of cake or heads of cattle.
The comparison of korean counters and how we say "pieces of ___" etc. Is helpful :d thx