"They eat cake."
Translation:Onlar pasta yerler.
It is totally fine and is just as correct as "yerler." If you state a plural subject, the -lAr suffix is optional on the verb. Consequently, if you decide to drop "onlar" when it is the subject pronoun, you have to use it to get the plural meaning on the verb :)
"They eat cake." - Onlar pasta yerler.
Your question is not stupid & is a valid Turkish grammar question warranting a reply.
The plural suffixes in Turkish -lar & -ler.
We use the rules of Major Vowel Harmony to decide which suffix to use.
Words whose last vowel is one of (a, ı, o, u) will get -lar added to it, while those whose last vowel is one of (e, i, ö, ü) will be followed by -ler.
The use of plurals.
The plural suffix is added to indicate plurality. If plurality is shown by a numeral greater than one or a word like “çok” (many), or “kaç” (how many), no plural suffix is added to the noun.
Dört armut - Four pears. The Turkish (noun) “armut” remains singular.
“Bankadan geliyorlar.” Last vowel “-o” use –lar. They are coming from the bank.
“Ofiste yumurta yiyorlar.” Last vowel “-o” use –lar. They are eating eggs in the office.
“Ördekler elma yer.” Last vowel “-e” use ler. The ducks eat apples. The noun is plural in the Turkish question & plural in the English answer. Plural nouns in Turkish don't need verb conjugation.
The plural suffix, lar/ler is not used with animals in Turkish.
“Ördekler elma yerler.” Wrong.
“Ördekler elma yer.” Correct.
if your purpose is not to state that you are talking about ONE cake spesifically, then its not used commonly. for example if you want to say "there was ONE cake in the bakery" like underlining the fact that there was one single cake left in there, you use "fırında BİR kek vardı." but if you want to say "there was a cake in the bakery" like just casually saying that there was a cake in there (maybe there were more but you just did not specify it) you use "fırında pasta vardı." ("fırın" means bakery. "vardı" means there was/were)
I understand that both 'onlar pasta yerler' and 'onlar pasta yer' are correct and mean the same thing.
There must be a difference colloquially though. Which do people use generally and how does this reflect in conversation? For instance if you used yerler all the time does it make you seem posh/well-spoken?
The proper rule is "if it is a group action, use singular, ie 'çocuklar bahçede toplandı' (the kids gathered in the garden); if the action is executed individually use the plural suffix, ie 'çocuklar ödevlerini yapıyorlar' (the kids are doing their homework).
However nobody follows this rule properly. So you can use either.
ph.ibUEKx, "yeriz"="we eat". In the English sentence we have "they". "Onlar" and "yeriz" do not work together. But: "biz yeriz" and "onlar yer(ler)". The suffix "ler" is optional because we already have the mark of the 3rd person plural in "on-lar". Also because there is only one verb with its subject.