Learn Turkish: Neden böyle bencilce düşünüyorsun? - Why are you thinking selfishly like this?

Bencil is an adjective meaning "selfish". By adding the -ce suffix, it turns into the adverb bencilce, meaning "selfishly" or "in a selfish way". Here, it describes how the action (düşünüyorsun) is being done.

Why did we use -ce instead of -ca or -çe for this word?

It comes down to vowel harmony and consonant rules. The last vowel in bencil is i (a front vowel), so the suffix must use e. Because the word ends in l, which is a soft or voiced consonant, the suffix starts with a soft c instead of a hard ç. This gives us -ce.

What exactly does böyle add to this sentence?

Böyle means "like this" or "in this way". In this sentence, it pairs with bencilce to mean "selfishly like this". It emphasizes the specific, current way the person is thinking.

Can you break down the suffixes on the verb düşünüyorsun?