Learn Turkish: Yalnız kalmaktan pek hazzetmediğini herkes biliyordu. - Everyone knew that she did not particularly enjoy being alone.

This is a compound verb made from the Arabic loanword haz (pleasure) and the auxiliary verb etmek (to do/make). When a loanword ending in a single consonant joins an auxiliary verb, the final consonant often doubles (gemination). Because a sound change occurs with the extra "z", Turkish spelling rules dictate that the compound must be written together as one single word: hazzetmek.

Why is the ablative suffix -tan added to kalmak here?

The verb hazzetmek (to enjoy or take pleasure in) requires its object to take the ablative case (-dan/-den). You can think of it literally as taking pleasure from doing something. Therefore, kalmak (to stay/to remain) becomes kalmaktan.

Can you break down the suffixes on hazzetmediğini?

The base is hazzet- (to enjoy) + -me (negative) + -diğ (the object participle -dik, with the "k" softened by the following vowel) + -i (third-person possessive, indicating "her" doing the action) + -n- (buffer letter) + -i (accusative case). The final accusative suffix is needed because this entire noun clause is the direct object of the main verb biliyordu.

Doesn't pek usually mean "very"? Why does the translation say "particularly"?