"These are difficult, those are easy."
Translation:Bunlar zor, şunlar kolay.
"These are difficult, those are easy." Translation: Bunlar zor, şunlar kolay.
Demonstrative pronouns - "İşaret zamirleri."
Bu - This(one) Şu - This(one), that(one) O - That(one) Bunlar - These. Şunlar - These, those. Onlar - Those.
The plural form of the demonstrative pronouns take the plural suffix "-lar" & the letter "-n" is added before the suffix "-lar."
"Bunlar zorlardır" would be understood to mean something like "These are the difficult ones"
Bunlar = these
zor = difficult
zor-lar = the difficult ones
zor-lar-dır = are the difficult ones
However, I don't know if "bunlar zorlardır" would really sound natural to a native speaker and I suspect that
"bunlar zor olanlar dır" - "these are the ones that are difficult"
would be much better.