Präsens
What is happening now, habits, and plans: morgen fahre ich.
- es sammelt sich an
- sie sammeln sich an
to accumulate
Weak verb, separable, reflexive, accusative, auxiliary haben.
Conjugated like angeln, klingeln, nieseln, hereinhoppeln, quasseln, sich wandeln
Separable: an
In a main clause, an goes to the end: es sammelt sich … an. It stays joined in a subordinate clause (…, dass es sich ansammelt), in the participle angesammelt, and with zu: anzusammeln.
Enough to talk about now, your plans, and what you did.
What is happening now, habits, and plans: morgen fahre ich.
The everyday past in speech: haben or sein plus the participle.
The past of stories, books, and the news. In speech, the Perfekt is more common.
Polite requests, wishes, and what would happen: ich würde gern…
Promises, predictions, and guesses about now: das wird stimmen. The present often says the future: morgen fahre ich.
A past action completed before another past action.
Hypotheses and wishes in one word. In speech, würde + infinitive replaces it, except for common verbs: käme, ginge, wüsste.
What would have happened, and regrets: wenn ich das gewusst hätte…
Reported speech, in the news and in writing, mostly with er, sie, es: sie sagt, er sei krank.
An action finished before a future moment, or a guess about the past: er wird es vergessen haben.