Learn Hardcore Turkish: Ben evde rahat ediyorum.

rahat etmek: to feel comfortable/at ease; to be in comfort. Natural in everyday speech.
rahat (adjective) + copula: Rahatım = I am comfortable (state).
rahat olmak: to be comfortable (more formal/literal; similar to rahatım).
rahatlamak: to relax, to become relieved (a change into comfort).
(kendimi) rahat hissetmek: to feel comfortable (often with reflexive: Kendimi rahat hissediyorum).

Why is it evde, not eve or evden?

Because -de/-da/-te/-ta is the locative case: at/in/on.

evde = at/in the house, at home.
eve (dative) = to the house.
evden (ablative) = from the house.
Rule of form: after a front vowel and a voiced final consonant, use -de → ev + de = evde. After voiceless finals you’d use -te/-ta (e.g., parkta).

How is ediyorum formed from etmek? Why not etiyorum?

Stem: et-
Present continuous: -(i)yor → with vowel harmony, -iyor
Voicing: t → d before a vowel → ediyor-
1st person singular: -um → ediyorum
So: et- + -iyor + -um → ediyorum (not etiyorum).

Could I say Ben evde rahatım instead? What’s the difference?

Yes.

Rahat ediyorum: emphasizes the ongoing feeling/experience (right now or in this situation).
Rahatım: a simple stative statement, “I am comfortable.” Both are fine; rahatım is shorter and slightly more descriptive than experiential.

Does evde mean “at home” or “in the house”?

Both, depending on context. In everyday speech, evde often means “at home.”
If you need to stress interior space versus outside, use evin içinde (inside the house) vs evin dışında (outside the house).

Can I specify “my home” with evimde?

Yes: Evimde rahat ediyorum = I feel comfortable in my home.
Without a possessive, evde often still implies “at (my) home” in conversation, unless context says otherwise.

How do I make this negative? What about “can’t feel comfortable”?

Negative (not feeling comfortable): Ben evde rahat etmiyorum.
Inability (can’t manage to feel comfortable): Ben evde rahat edemiyorum.
The second implies some obstacle preventing comfort.

How do I ask a yes/no question with this sentence?

Use the question particle mi after the predicate:

2nd person: Evde rahat ediyor musun?
1st person: Ben evde rahat ediyor muyum?
3rd person: Evde rahat ediyor mu?
Note vowel harmony: mi/mi/mu/mü, and personal endings attach to mi (e.g., musun, muyum).

What are the word-order options and what do they emphasize?

Turkish is flexible, but keep natural groupings:

Evde rahat ediyorum. (neutral; place focus)
Ben evde rahat ediyorum. (subject contrast/emphasis)
Rahat ediyorum evde. (end-focus on place: “It’s at home that I feel comfortable.”)
Avoid splitting rahat far from ediyorum without a good reason.

Is de here the same as the separate particle de/da meaning “also/too”?

No. In evde, -de is a suffix (locative case) and is written attached.
The additive particle is separate: Ben de evde rahat ediyorum = I also feel comfortable at home.

Can I use other tenses with rahat etmek?

Yes:

Past: Dün evde rahat ettim.
Past continuous: Evde rahat ediyordum.
Future: Evde rahat edeceğim.
Necessity: Evde rahat etmeliyim.
Ability: Evde rahat edebilirim.
Note the spellings: ettim, edeceğim, edebilirim.

Any pronunciation tips for this sentence?

evde: say it as two syllables, ev-de (not “ef-te”).
rahat: clear h; two syllables ra-hat.
ediyorum: e-di-yo-rum; the d is voiced (not “etiyorum”).
Turkish usually stresses the last syllable: ev-DE, edi-yo-RUM.

Can I use hissetmek here?

Yes: Evde kendimi rahat hissediyorum.

With hissetmek (to feel), it’s common to include the reflexive kendimi.
You’ll also hear Evde rahat hissediyorum, but the version with kendimi is more complete/natural.

When would I use the simple present rahat ederim instead of rahat ediyorum?

Use rahat ederim for general truths/habits:

Evde rahat ederim = I (generally) feel comfortable at home.
Use rahat ediyorum for right now or a specific current situation.