Learn Hardcore German: Das Kind lacht laut, als der Hund durch das Haus läuft. - The child laughs loudly as the dog runs through the house.

In German, als can mean as in the sense of at the same time or when for a specific event in the past. Even though we often learn that als is used for past events, it can also be used in a present tense sentence to link two actions occurring simultaneously. Using wenn would sound more conditional (like if or whenever). In this sentence, als emphasizes that both actions—the child laughing and the dog running—are happening at the same time.

Is laut functioning as an adjective or an adverb in this sentence?

In German, many adjectives can serve as adverbs without changing form. Here, laut modifies the verb lacht. We consider it an adverb in meaning (describing how the child laughs). The form is the same as the adjective laut (“loud”), but it’s describing the manner of the action, so it’s acting adverbially.

Why do we say durch das Haus and not something else like im Haus?

The preposition durch indicates movement through or across something. Here, it shows the dog’s path going from one part of the house to another. If you said im Haus, it would mean the dog is simply inside the house, without emphasizing movement through it.

How do we get the form läuft from laufen?

Laufen is an irregular (strong) verb in German. In the present tense, third-person singular (er/sie/es), it changes its stem from lauf- to läuf-, also adding the t ending:
• ich laufe
• du läufst
• er/sie/es läuft
• wir laufen
• ihr lauft
• sie/Sie laufen

Could we use rennt (“runs quickly”) instead of läuft here?

Yes, we could use rennt if we want to emphasize fast or hurried running. However, laufen is more neutral and can mean to run or to walk depending on context. Rennen always implies a faster pace.

Does als change the word order in the second clause?

Yes. When als introduces a subordinate clause, the conjugated verb—läuft—goes to the end of that clause in writing. But the sentence here is structured a bit differently to keep it flowing naturally. If you used a fully standard subordinate clause structure, it would be …, als der Hund durch das Haus läuft with the verb at the end. In practice, though, many speakers keep a more conversational word order. If you strictly follow the rule, the verb should be at the end of the subordinate clause: als der Hund durch das Haus läuft.