Learn Turkish: Ben bu denizde sörf yapabilirim.

This word uses the Turkish ability suffix -abil, which means "can" or "is able to". It is made up of the verb root yap (do), the ability suffix -abil, the general (aorist) tense marker -ir, and the personal ending -im (I). Put together, yap-abil-ir-im translates to "I can do".

Why is the verb yapmak (to do) used here instead of a single verb for "surf"?

In Turkish, sörf is a borrowed word that acts as a noun meaning "surfing". To express the action of surfing, Turkish uses a compound verb with the helper verb yapmak (to do). So, "to surf" is expressed literally as "to do surfing" (sörf yapmak).

Why include the pronoun Ben (I) if the verb already ends with -im?

You don't have to! The ending -im on yapabilirim already makes it perfectly clear who is doing the action. Adding the pronoun Ben at the start of the sentence just adds emphasis, similar to saying "I am the one who can surf in this sea."

Why does deniz (sea) have the suffix -de?

The suffix -de is the locative case, which tells us where an action happens (meaning "in", "on", or "at"). Because of Turkish vowel harmony rules, words ending with front vowels like the "i" in deniz take -de instead of -da. Therefore, denizde means "in the sea".