Learn Hardcore Turkish: Sessiz ortamda rahat ediyorum. - I feel comfortable in a quiet environment.

Rahat ediyorum: right now/around now, or a currently relevant state (“I’m comfortable [in this setting]”).
Rahat ederim: habitual or general tendency (“I do well/I tend to be comfortable [in quiet places]”). Choose based on whether you mean a current situation or a general preference.

It’s a light-verb construction: rahat (comfort/comfortable) + etmek (to do). Together, rahat etmek means “to be/feel comfortable, to be at ease.” It describes a state of comfort rather than “making someone comfortable.”

Why is it ediyorum and not etiyorum?

With etmek, when a vowel-initial suffix is added (like the progressive -iyor), the stem-final t often voices to d: et- + -iyor → ediyor. So you get rahat ediyorum. This also happens with some other verbs (e.g., gitmek → gidiyor), but not with all verbs ending in t (e.g., satmak → satıyorum, not “sadıyorum”).

Can you break the sentence into parts so I see how it’s built?

sessiz = quiet (adjective)
ortam = environment
-da = locative suffix “in/at/on” → ortamda = in a(n) environment
rahat = comfortable/comfort
et- = to do (forms the verb with rahat)
-iyor = present continuous/progressive
-um = 1st person singular Altogether: “In a quiet environment, I am/feel comfortable.”

Why is it -da and not -de/-ta/-te on ortam?