Learn Hardcore German: Ich suche einen Becher mit Deckel, damit der Kaffee nicht ausläuft. - I am looking for a cup with a lid so that the coffee doesn’t spill.

Because Becher is masculine (der Becher) and it’s the direct object of suchen, which takes the accusative. Masculine accusative singular uses -en: einen Becher. Nominative would be ein Becher; dative would be einem Becher.

Shouldn’t it be mit einem Deckel? Why is there no article in mit Deckel?

Both are possible. Mit governs the dative, so the fully expressed form is mit einem Deckel. However, in short descriptive phrases after a noun (especially product-style descriptions), German often drops the article: Becher mit Deckel, Tasse mit Henkel, Salat ohne Dressing. It’s idiomatic and concise.

Why is it der Kaffee and not dem Kaffee in the second clause?

In damit der Kaffee nicht ausläuft, der Kaffee is the subject of the clause, so it’s nominative (der). Dem Kaffee would be dative and would be wrong here.

Why does the verb appear as ausläuft at the end, not läuft aus?

Damit introduces a subordinate clause, which sends the finite verb to the end. With separable verbs like auslaufen, the prefix reattaches in subordinate clauses: main clause → Der Kaffee läuft nicht aus; subordinate clause → …, damit der Kaffee nicht ausläuft.

What exactly does damit do here? How is it different from dass or sodass and from um … zu?

Damit means “so that/in order that” and expresses intended purpose: …, damit der Kaffee nicht ausläuft.
Dass introduces a content clause, not purpose, and wouldn’t be correct here.
Sodass (so dass) expresses (often unintended) result: …, sodass der Kaffee nicht ausläuft = “with the result that…”.
Um … zu also expresses purpose but requires the same subject in both clauses. Here the main clause subject (ich) is not the one that can “leak,” so damit is the natural choice. You could recast with um only by changing the verb: …, um Verschütten zu vermeiden.

Why use nicht and not kein before ausläuft?

Use nicht to negate a verb phrase: nicht ausläuft. Kein negates nouns. You could say …, damit kein Kaffee ausläuft if you mean “so that no coffee (at all) spills,” but that slightly shifts the meaning from a specific coffee (der Kaffee) to coffee in general/any coffee.

Does suchen need a preposition like English “look for”? What about nach … suchen?

German allows both:

Transitive: Ich suche einen Becher (neutral and very common).
Prepositional: Ich suche nach einem Becher (focuses a bit more on the ongoing act of searching). Both are correct; choose based on nuance or style.

What’s the difference between Becher and Tasse?

Becher: a beaker/tumbler-style cup; often taller, can be plastic/paper; commonly used for to‑go coffee; may or may not have a handle.
Tasse: a mug/cup, usually ceramic/porcelain with a handle, used at home or in cafés. For a lidded to-go cup, Becher (mit Deckel) is the natural choice.

What does auslaufen mean here, and is it the same as “run out” (be used up)?

Here auslaufen means “to leak/spill/run out (of a container).” It’s not the same as “run out” in the sense of “be used up,” which is ausgehen: Der Kaffee ist ausgegangen = “We’ve run out of coffee.”

Could I add mir: …, damit mir der Kaffee nicht ausläuft?

Yes. Adding mir (dative of interest) is idiomatic and means “so that the coffee doesn’t spill on me/for me,” highlighting who is affected. It’s optional and more colloquial.

Why is there a comma before damit?

German requires a comma before a subordinate clause. Damit is a subordinating conjunction, so you must separate the clauses with a comma.

What are the genders of Becher, Deckel, and Kaffee?

All three are masculine:

der Becher
der Deckel
der Kaffee That’s why you see forms like einen Becher, mit (einem) Deckel, der Kaffee.

How would this look in the plural?

Plural nouns: Becher (same form), Deckel (same form), Kaffees (rare; usually means different types).
With mit
- dative plural, add -n if possible: Becher mit Deckeln (“cups with lids”). In product-style labels you still often see the articleless pattern: Becher mit Deckel even for sets, but the grammatically explicit plural is mit Deckeln.

Can I say Becherdeckel instead of Becher mit Deckel?

Becherdeckel means “cup lid” (the lid itself), not “cup with a lid.” If you want the cup that has a lid, say Becher mit Deckel. If you’re talking about the lid as an item, Becherdeckel fits.

How do I form the perfect tense with auslaufen?

Use sein as the auxiliary: Der Kaffee ist ausgelaufen (“The coffee has leaked/spilled out”). With suchen, use haben: Ich habe einen Becher gesucht.