Learn Hardcore German: Plötzlich fällt mir ein, dass wir noch Brot kaufen müssen. - Suddenly it occurs to me that we still have to buy bread.

Because the verb is einfallen (to occur to someone / to suddenly come to mind), which takes the person as an indirect object in the dative. So the idea “falls in” to me: jemandem fällt etwas ein. Hence dative mir, not accusative mich.

What is the subject of “fällt”? Why is the verb 3rd person singular?

The subject is the content clause dass wir noch Brot kaufen müssen (“that we still have to buy bread”). That whole clause is grammatically singular, so the verb is 3rd person singular: fällt. In many sentences with such clauses, German also uses an expletive es (“it”): Es fällt mir ein, dass …

Can/should I include “es”? Is “Plötzlich fällt es mir ein, dass …” also correct?

Yes. Both are idiomatic:

Plötzlich fällt mir ein, dass … (es omitted)
Plötzlich fällt es mir ein, dass … (with expletive) Including es is very common and a bit clearer in writing. Omitting it is frequent in speech and perfectly fine here.

Why is “ein” at the end of the main clause? Isn’t the verb “fallen”?

Einfallen is a separable-prefix verb. In a main clause, the finite part goes to position 2 (fällt) and the separable prefix goes to the clause-final “right bracket” (… fällt … ein). In a subordinate clause, prefix and stem stay together at the end: … dass es mir plötzlich einfällt …

What does “noch” mean here?

Here noch means “still / yet,” expressing an unfulfilled task: we haven’t bought bread yet and it’s still required. It does not mean “another” by default in this sentence.

Could “noch” mean “more” here?

Not in this exact structure. Compare:

Wir müssen noch Brot kaufen. = We still need to buy bread (it’s not done yet).
Wir müssen mehr Brot kaufen. = We need to buy more bread (a larger quantity).
Wir müssen noch mehr Brot kaufen. = We still need to buy more bread (both ideas).
noch ein Brot = another loaf of bread.

Where does “noch” go? Could I say “dass wir Brot noch kaufen müssen”?

Best placement is early in the verb phrase: dass wir noch Brot kaufen müssen. “Brot noch” is possible only with special emphasis and usually sounds marked. A very natural main-clause variant is: Wir müssen noch Brot kaufen.

Why is there no article before “Brot”?

Brot is used as an uncountable/mass noun here. When you talk about buying bread in general, German often omits the article: Brot kaufen. If you mean a specific loaf previously mentioned, you’d use das Brot.

Would “das Brot” change the meaning?

Yes. Wir müssen noch das Brot kaufen implies a particular bread already known from context (e.g., the loaf you reserved). Wir müssen noch Brot kaufen means bread in general; any bread will do.

Why is the verb order “kaufen müssen” at the end of the dass-clause?

In subordinate clauses, the finite verb goes to the end. With modals, the main verb (infinitive) precedes the modal: … kaufen müssen. So: dass wir noch Brot kaufen müssen (not “müssen kaufen” in a dass-clause).

How would this look in the past tense?

Simple past: Plötzlich fiel mir ein, dass wir noch Brot kaufen müssen.
More commonly with this verb: perfect: Plötzlich ist mir eingefallen, dass wir noch Brot kaufen müssen. Note the auxiliary sein with einfallen: ist … eingefallen.

What’s the difference between “einfallen” and “(sich) erinnern”?

Mir fällt ein, … = It occurs to me / I suddenly remember (spontaneous recollection).
Ich erinnere mich (daran), … = I remember (more deliberate recall). Both can express remembering, but einfallen emphasizes the sudden, involuntary nature.

Why is there a comma before “dass”? And why “dass” with double s?

German requires a comma before subordinate clauses introduced by subordinating conjunctions like dass. Since the spelling reform, the conjunction is spelled dass (with ss). Das is the article/relative pronoun (“the/which/that” in other senses).

Could I replace “plötzlich” with “auf einmal”?

Yes. Auf einmal is a very natural, slightly more colloquial alternative to plötzlich. Both mean “suddenly.” Slight nuance: plötzlich can sound a bit more neutral/formal; auf einmal can also mean “all at once.”

Is “Mir fällt plötzlich ein, …” also correct? Why is the verb still second?

Yes. In main clauses German is verb-second. If you front Mir or Plötzlich, the finite verb fällt remains in second position:

Plötzlich fällt mir ein, …
Mir fällt plötzlich ein, … Both are fine; you’re just changing the emphasis.

Could I drop “dass” and say “Plötzlich fällt mir ein, wir müssen noch Brot kaufen”?

In casual speech people do this. In standard writing, keep dass or use punctuation to mark the new clause:

Plötzlich fällt mir ein, dass wir noch Brot kaufen müssen. (standard)
Plötzlich fällt mir ein: Wir müssen noch Brot kaufen. (also fine)

What’s the difference between “kaufen” and “einkaufen” here?

Brot kaufen = to buy bread (the act of purchasing that item).
Brot einkaufen = also possible; einkaufen often means “do the shopping (for groceries).”
einkaufen gehen = go shopping (general). So Wir müssen noch Brot einkaufen is fine and sounds like part of the grocery run.

Why does “fallen” have an umlaut here (fällt)?

Fallen is a strong verb with vowel change in 2nd/3rd person singular present: ich falle, du fällst, er/sie/es fällt; wir fallen, ihr fallt, sie fallen. Hence fällt.

Can “einfallen” take a noun instead of a dass-clause?

Yes: Mir fällt ein Name ein. / Ihr fiel plötzlich eine Idee ein. You can also use an infinitive clause: Mir fällt ein, noch Brot kaufen zu müssen (grammatical but more formal/literary than using a dass-clause).

How would I turn the content into a direct question?

From the embedded clause: Müssen wir noch Brot kaufen? In a main clause statement: Wir müssen noch Brot kaufen. Question: Müssen wir noch Brot kaufen?