Learn Hardcore German: Der Trainer motiviert uns jeden Morgen.

Uns is the accusative (direct object). The verb motivieren takes a direct object: Wen/Was motiviert der Trainer? → uns.
Wir is nominative and can only be the subject. For 1st person plural: nominative wir, accusative/dative uns.

Why der Trainer and not den Trainer?

Because der Trainer is the subject (nominative masculine singular → der).
If it were the object, you’d use accusative: Ich sehe den Trainer.

What tense and person is motiviert?

Present tense (Präsens), 3rd person singular of motivieren.
Mini pattern: ich motiviere – du motivierst – er/sie/es motiviert – wir motivieren – ihr motiviert – sie motivieren.

Is motivieren separable or irregular? And why is the participle without ge-?

motivieren is a regular verb ending in -ieren.
Verbs in -ieren form their participle without ge-: hat motiviert, not hat gemotiviert.
It is not separable.

Why jeden Morgen and not jeder Morgen?

It’s a time expression using a masculine noun (der Morgen) in the accusative: masculine accusative of jeder is jeden.
Masculine forms of jeder: nominative jeder, accusative jeden, dative jedem, genitive jedes.

Why is Morgen capitalized? Is it the same as morgen?

Morgen (capitalized) = the noun “morning” (der Morgen).
morgen (lowercase) = the adverb “tomorrow.”
Examples:
Der Trainer motiviert uns jeden Morgen.
Der Trainer motiviert uns morgen.

Where can jeden Morgen go in the sentence?

German allows flexible word order, but the finite verb stays in 2nd position. Common and natural options:

Der Trainer motiviert uns jeden Morgen. (neutral)
Jeden Morgen motiviert uns der Trainer. (fronted time for emphasis)

“Der Trainer motiviert jeden Morgen uns” is grammatical but sounds marked; short pronouns like uns prefer to appear right after the verb.

Can I say am jeden Morgen?

No. Use either:

jeden Morgen (most common), or
an jedem Morgen (with preposition, more formal/emphatic).

Note: am Morgen = “in the morning” (on a given day), but am jeden Morgen mixes patterns and is incorrect.

What’s the difference between jeden Morgen and morgens?

jeden Morgen = every single morning (stronger, more explicit).
morgens = in the mornings, generally/habitually (softer, more generic).
Both often translate to “every morning,” but jeden Morgen stresses regularity a bit more.

Why is the verb in second position?

German main clauses are verb-second (V2). One element (subject, time phrase, etc.) can come first, and the finite verb must be second:

Der Trainer | motiviert uns jeden Morgen.
Jeden Morgen | motiviert uns der Trainer.

How would I turn it into a subordinate clause?

In subordinate clauses the finite verb goes to the end:

Ich glaube, dass der Trainer uns jeden Morgen motiviert.
Wir kommen pünktlich, weil der Trainer uns jeden Morgen motiviert.

How do I put it in the past?

Spoken German (Perfekt): Der Trainer hat uns jeden Morgen motiviert.
Written/narrative (Präteritum): Der Trainer motivierte uns jeden Morgen.

How do I make it passive?

Action passive (Vorgangspassiv): Wir werden jeden Morgen vom Trainer motiviert.
Note: State passive (Zustandspassiv) would be: Wir sind jeden Morgen motiviert (we are in a motivated state), which describes a result/state, not the action.

How would the sentence look with a female coach?

Die Trainerin motiviert uns jeden Morgen.

How does it change with plural coaches?

Subject and verb agree in plural: Die Trainer motivieren uns jeden Morgen.

Can I omit the article and say “Trainer motiviert uns …”?

Generally no. With specific people, German uses articles: Der Trainer. Dropping it sounds like a headline or a note, not normal prose.

How can I check the case of uns quickly?

Use the question test: Wen/Was motiviert der Trainer? → uns (accusative).
Compare with a dative verb: Der Trainer hilft uns (Wem hilft der Trainer? → uns).

Can motivieren be reflexive?

Yes, when the subject motivates itself: Der Trainer motiviert sich jeden Morgen.
That means “The coach motivates himself …” (not “us”).

How do I pronounce motiviert?

Stress on the last syllable: mo-ti-VIERT.
The v is pronounced like English “v” (not “f”), and ie is a long “ee” sound. Approx. IPA: [moːtiˈviːɐ̯t].

Is “Der Trainer motiviert jeden Morgen” (without an object) okay?

Not really. motivieren is normally transitive and sounds incomplete without an object. Use an object like uns, die Mannschaft, etc.