In a normal German main clause, the conjugated verb sits in the second position — always. “Second” means the second sentence element, not the second word: a whole time phrase like “Am Montag” counts as one element.
Ich trinke morgens Kaffee.
I drink coffee in the mornings.
1: Ich · 2: trinke ✓
Morgens trinke ich Kaffee.
In the mornings I drink coffee.
1: Morgens · 2: trinke · then ich
Heute Abend gehe ich ins Kino.
Tonight I'm going to the cinema.
The whole phrase 'Heute Abend' is element 1.
Whatever you put first, the verb stays put
If you begin with something other than the subject (a time, a place, an object) to add emphasis, the subject simply jumps to just after the verb. The verb never moves from slot two. This subject-after-verb swap is called inversion.
The exceptions to know
- Yes/no questions and commands put the verb first: “Trinkst du Kaffee?”, “Komm her!”
- The coordinating conjunctions und, aber, oder, denn, sondern don't count as a position — the verb still comes second after them: “…, aber ich trinke Tee.”
- Subordinating conjunctions (weil, dass, wenn…) send the verb to the very end — that's a different rule.
✗Morgen ich gehe zum Arzt.
✓Morgen gehe ich zum Arzt.
After the front time phrase, the verb must be second, so subject and verb swap.
✗Weil er ist müde.
✓Weil er müde ist.
weil is subordinating — the verb goes to the end.
Tipp · Say the sentence and point at the first element, then the verb should be the next thing out of your mouth. If it isn't, rearrange.