Learn Hardcore German: Abends sitze ich wieder im Wohnzimmer, trage meinen Pyjama und fühle mich ruhig. - In the evening I sit again in the living room, wear my pyjamas and feel calm.

Abends (with -s) is an adverb meaning “in the evenings / at night (as a habit)”.
- It describes something that happens regularly in the evening.
am Abend = “in the evening” but usually refers to one specific evening or a specific time frame.

Examples:

Abends lese ich gern. – In the evenings I like to read. (habit)
Am Abend lese ich ein Buch. – In the evening I read a book. (today / on that evening)

So in your sentence, “Abends” implies a regular, repeated routine.

Is “Abends” a noun? Why is it capitalized?

No, “abends” is normally an adverb and would be written with a lowercase a in the middle of a sentence.

It is capitalized here only because it is the first word of the sentence.
If it came in the middle, you would write:

Ich bin müde, abends sitze ich wieder im Wohnzimmer.

Why is the word order “Abends sitze ich …” and not “Abends ich sitze …” or “Ich sitze abends …”?

German main clauses follow the verb-second rule (V2):

The finite verb (here: sitze) must be in second position in the sentence.
The first position can be the subject or some other element (time, place, etc.).

So both are correct:

Ich sitze abends wieder im Wohnzimmer. (Subject in position 1)
Abends sitze ich wieder im Wohnzimmer. (Time in position 1; verb must still be 2nd)

But “Abends ich sitze …” is wrong because that would put the verb in third position.

Why is there no “ich” before “trage” and “fühle mich”?

There is one subject “ich” at the beginning, and it is understood to apply to all three verbs:

(Ich) sitze …, (ich) trage … und (ich) fühle mich …

In German (and English) you can omit repeated subjects in a list:

English: In the evening I sit in the living room, wear my pyjamas and feel calm.
German: Abends sitze ich …, trage meinen Pyjama und fühle mich ruhig.

If you want, you can repeat ich:

Abends sitze ich wieder im Wohnzimmer, ich trage meinen Pyjama und ich fühle mich ruhig.

This is grammatically fine, but stylistically heavier; most natives would omit the repetitions here.

Why is there a comma before “trage”, and then “und” before “fühle mich”?

You have three main clauses with the same subject:

(Ich) sitze wieder im Wohnzimmer,
(ich) trage meinen Pyjama
und (ich) fühle mich ruhig.

In lists of clauses, German normally:

Separates parts 1 and 2 with a comma,
And connects the last one with “und” (or “oder”).

That’s parallel to English:

I sit in the living room, wear my pyjamas and feel calm.

What exactly does “wieder” mean in this sentence, and could it go somewhere else?

Here wieder means “again / back again / once more”. The idea is: in the evenings, the speaker is back in the living room.

The position “Abends sitze ich wieder im Wohnzimmer” is very natural.
Other possible positions (with slightly different emphasis):

Abends sitze ich im Wohnzimmer wieder. – possible, but sounds odd here.
Abends sitze ich wieder im Wohnzimmer – best choice.

In most cases, put wieder in the “middle field” before the place/time phrase, just as in the original sentence.

What does “im Wohnzimmer” literally mean? Why “im” and not “in das Wohnzimmer”?

im is a contraction of in dem:

in (in) + dem (the – dative, neuter) → im

Wohnzimmer is neuter: das Wohnzimmer.
After the preposition in, you use:

Dative if it’s about location (Where?):
- Ich sitze im Wohnzimmer. – I am sitting in the living room.
Accusative if it’s about movement towards something (Where to?):
- Ich gehe ins Wohnzimmer. = in + das (accusative) Wohnzimmer.

In your sentence, it’s about location (where I sit), so dative: im Wohnzimmer is correct.

Why “meinen Pyjama” and not “mein Pyjama”?

The verb tragen (to wear/carry) takes a direct object in the accusative.

Nominative: der Pyjama (masculine)
Accusative: den Pyjama

With mein, you must match the case and gender:

Nominative masculine: mein Pyjama
Accusative masculine: meinen Pyjama

So:

Ich trage meinen Pyjama. – I am wearing my pyjamas. (correct)
✗ Ich trage mein Pyjama. – wrong in standard German.

What is the difference between “tragen” and other ways to say “to wear”?

Common options:

tragen – to wear (clothes, glasses, jewellery)
- Ich trage meinen Pyjama. – I’m wearing my pyjamas.
anhaben – to have on (more colloquial)
- Ich habe meinen Pyjama an.
anhaben vs tragen:
- tragen can also mean to carry: Ich trage eine Tasche.
- anhaben is only for having clothes on your body.

All of these would be understood, but tragen is neutral and very common.

Why do we say “fühle mich ruhig” and not just “fühle ruhig”?

In German, sich fühlen is a reflexive verb when you talk about your emotional/physical state:

Ich fühle mich ruhig. – I feel calm.
Ich fühle mich schlecht. – I feel bad.
Ich fühle mich müde. – I feel tired.

The pattern is:

sich fühlen + Adjektiv

You need the reflexive pronoun:

ich fühle mich
du fühlst dich
er/sie/es fühlt sich
wir fühlen uns
ihr fühlt euch
sie/Sie fühlen sich

So “fühle ruhig” without mich is incorrect in this meaning.

What nuance does “ruhig” have here? Is it “calm”, “quiet”, or “peaceful”?

ruhig can mean:

calm / peaceful (emotionally):
- Abends fühle ich mich ruhig. – I feel calm in the evenings.
quiet / not loud (environment):
- Es ist hier sehr ruhig. – It is very quiet here.

In your sentence, it clearly refers to the emotional state (“I feel calm/peaceful”), not to being physically silent.

Why is the present tense used? Could it be something like “werde sitzen” or a past tense?

German often uses the present tense for:

General habits / routines,
Timeless facts.

Your sentence describes a regular routine, so Präsens is natural:

Abends sitze ich …, trage … und fühle mich ruhig.
= “In the evenings, I (usually) sit…, wear…, and feel…”

You could use other tenses depending on context:

Past (narration):
- Abends saß ich wieder im Wohnzimmer, trug meinen Pyjama und fühlte mich ruhig.
Future (unusual here):
- Abends werde ich wieder im Wohnzimmer sitzen … – I will sit… (talking about future plans)

But for a general description of your routine, the plain present is the standard choice.

Could I say the sentence in a different, but still correct, way?

Yes, several variations are natural. For example:

Ich sitze abends wieder im Wohnzimmer, trage meinen Pyjama und fühle mich ruhig.
Abends bin ich wieder im Wohnzimmer, trage meinen Pyjama und fühle mich ruhig.
Abends sitze ich wieder im Wohnzimmer, ich trage meinen Pyjama und ich fühle mich ruhig. (more emphasis on each “ich”)

All of these are grammatically correct; the original has a smooth, natural flow.