Learn Hardcore German: Trotz des langen Tages in der Mensa und im Seminar fühle ich mich am Abend erstaunlich locker. - Despite the long day in the cafeteria and in the seminar, I feel surprisingly relaxed in the evening.

trotz des langen Tages
- des = genitive singular article (masculine/neuter)
- langen = adjective in genitive masculine singular
- Tages = genitive singular of der Tag

So the phrase is literally: “despite the long day” → trotz des langen Tages.

You will sometimes hear trotz dem langen Tag (dative) in spoken, colloquial German, but it is considered non‑standard in careful written German. If you’re learning, you should stick to trotz + genitive.

How do the endings in des langen Tages work exactly?

Breakdown of des langen Tages:

Tag (day) is masculine: der Tag (nom. sing.)
Genitive singular masculine of the article der is des.
In the genitive singular, masculine and neuter nouns often take an extra -s or -es:
- der Tag → des Tages
- (like English: day → day’s)
The adjective before a genitive noun with a definite article takes -en:
- lang → langen

So:

der lange Tag (nominative)
trotz des langen Tages (genitive after trotz)

Why is it in der Mensa but im Seminar?

Two things are going on here: gender and contraction.

Case (dative)
Both Mensa and Seminar are locations where something happens. With in meaning “in/inside” in a static sense (no movement), German uses the dative:
- in der Mensa – in the cafeteria
- in dem Seminar – in the seminar (room/session)
Gender and contraction
- die Mensa (feminine) → dative singular: der
- in der Mensa
- das Seminar (neuter) → dative singular: dem
- in dem Seminar → commonly contracted to im Seminar

So im is just in + dem. The sentence could also be written more “expanded” as:

… in der Mensa und in dem Seminar … but in practice people almost always say im Seminar.

What exactly is a Mensa? It doesn’t look like the English word “mess hall” or “canteen”.

In German, die Mensa almost always means:

the cafeteria/canteen at a university or college, where students (and often staff) eat.

It does not mean “month” or anything related to the English word “menses”; that similarity is accidental.

Typical translations:

die Mensa → the student cafeteria, the university canteen

Culturally, the Mensa is part of student life in German‑speaking countries, usually offering subsidized meals for students.

Why does the verb come before the subject in fühle ich mich instead of ich fühle mich?

German main clauses are verb‑second (V2), not necessarily subject‑first.

The first position in the sentence is taken by the whole phrase:

Trotz des langen Tages in der Mensa und im Seminar → Position 1

Because the verb must be in second position, it comes next:

fühle → Position 2

Everything else follows, including the subject:

ich (subject)
mich (reflexive pronoun)
am Abend erstaunlich locker (rest of the predicate)

So the structure is:

Trotz des langen Tages in der Mensa und im Seminar
fühle
ich
mich am Abend erstaunlich locker.

If you start the sentence with Ich, you can say:

Ich fühle mich am Abend trotz des langen Tages … locker.

Both are correct; the choice changes emphasis, not grammar.

Why do we need mich in fühle ich mich? Could you just say ich fühle am Abend locker?

fühlen can be:

Reflexive: sich fühlen = to feel (a certain way)
- Ich fühle mich müde. – I feel tired.
- Ich fühle mich locker. – I feel relaxed.
Non‑reflexive: etwas fühlen = to feel something (physically or emotionally)
- Ich fühle den Stoff. – I feel the fabric.
- Ich fühle Schmerzen. – I feel pain.

In the sentence, fühle ich mich … locker, we’re talking about my internal state, so German uses the reflexive form: ich fühle mich ….

Ich fühle am Abend locker sounds incomplete/wrong because without mich, fühlen expects some object like “the chair”, “the cold”, etc., not an adjective.

What does am Abend mean exactly, and why is it not im Abend or am Abends?

am Abend literally is an dem Abend (preposition + article):

an (on, at) + dem (dative masculine of der Abend)
→ am Abend

Usage:

am Abend – in the evening / at night (that evening, or as a general time of day)

A few points:

Time expressions with Tageszeiten (times of day) often use am:
- am Morgen, am Nachmittag, am Abend
You don’t say im Abend in standard German for time; im is used with months/seasons/etc.:
- im Januar, im Sommer
abends (with -s) is an adverb meaning “in the evenings” (regularly, habitually):
- Ich fühle mich abends locker. – I (generally) feel relaxed in the evenings.
am Abend can be more like “(on) this evening/that evening” or a particular evening, though it can also be generic depending on context.

What is the function of erstaunlich in am Abend erstaunlich locker? Is it an adjective or an adverb?

In am Abend erstaunlich locker, the structure is:

locker – adjective describing how I feel (predicate adjective)
erstaunlich – an adverbial intensifier (“surprisingly”)

German often uses the same form for adjectives and adverbs. Here, erstaunlich is modifying locker, not a noun, so it’s behaving like an adverb:

locker – relaxed, loose
erstaunlich locker – surprisingly relaxed

You could translate:

Ich fühle mich am Abend erstaunlich locker.
→ “In the evening, I feel surprisingly relaxed.”

What does locker mean here? I know locker can mean “loose”.

You’re right: locker can be physical (loose), but it also has a figurative meaning.

Physical:

Die Schraube ist locker. – The screw is loose.

Figurative / about a person or mood:

Ich bin heute ganz locker. – I’m very relaxed/easygoing today.
Die Atmosphäre war locker. – The atmosphere was relaxed, informal.

In the sentence, locker clearly refers to how the person feels after a long day, so it means:

relaxed, chilled, loose in the sense of not tense or stressed.

So the idea is: “Despite the long day, I feel surprisingly relaxed in the evening.”

Could I also say Obwohl der Tag lang war, fühle ich mich am Abend erstaunlich locker instead of using trotz des langen Tages? What’s the difference?

Yes, you can, and both are correct, but they differ slightly in structure and nuance.

With trotz
- noun (genitive):
- Trotz des langen Tages … fühle ich mich … locker.
- “Despite the long day, I feel relaxed…”
Here, trotz directly introduces a noun phrase (des langen Tages).
With obwohl
- clause:
- Obwohl der Tag lang war, fühle ich mich … locker.
- “Although the day was long, I feel relaxed…”
Here, obwohl introduces a subordinate clause (obwohl der Tag lang war).

In meaning, both express concession/contrast (“even though / despite”), and in most contexts they’re interchangeable.

Stylistic differences:

trotz + Genitiv is compact and somewhat more formal or written.
obwohl + Verb-final clause is more neutral and very common in spoken language.

So your alternative sentence is perfectly valid; it just uses a different grammatical construction to express the same idea.