Learn Turkish: Yemek iğrençti, ayrıca onun şakalarına katlanmak çok zordu. - The food was disgusting; furthermore, it was very hard to put up with his jokes.

ayrıca connects two independent thoughts, meaning 'furthermore' or 'additionally' (it comes from ayrı, meaning 'separate'). You could easily use üstelik here instead! While ayrıca just adds another point, üstelik gives a slightly stronger feeling of 'and on top of all that...', which fits perfectly when complaining.

Why does şakalarına end with the dative case -a?

The verb katlanmak (to put up with / to endure) always requires the dative case (-e/-a) for the thing you are enduring. In Turkish, you don't put up 'with' something; you put up 'to' it.

Can you break down all the suffixes attached to şaka (joke)?

Yes! It starts with şaka (joke). Then -lar makes it plural (jokes). The -ı is the possessive suffix matching onun (his jokes). The -n- is a buffer letter that must be used whenever you attach a case ending to a possessive suffix, and finally the -a is the dative case needed for the verb katlanmak.

Why does the past tense ending look different on iğrençti versus zordu?