Learn Hardcore German: Die Maus bewegt sich lautlos durch das Haus. - The mouse moves silently through the house.

In German, sich bewegen is a reflexive verb meaning “to move oneself” or simply “to move” intransitively. Without sich, bewegen is transitive (“to move something”), e.g. Er bewegt den Stuhl (“He moves the chair”). To express that the subject moves by itself, you need the reflexive pronoun: Die Maus bewegt sich.

What case does the preposition durch require, and why is it das Haus here?

durch always governs the accusative case. Since Haus is a neuter noun, its singular accusative article is das (the same form as the nominative). Hence durch das Haus.

Why doesn’t lautlos have an ending like lautlose or lautloses?

Here lautlos functions as an adverb modifying the verb bewegt. German adverbs are not declined, so they remain in their base form. Only adjectives directly preceding a noun (attributive adjectives) would take endings.

Why is lautlos placed before durch das Haus instead of after it?

German word order often follows the pattern Verb – Manner – Place – Time. lautlos (manner) comes right after the verb phrase bewegt sich, and durch das Haus (place) follows. You could say Die Maus bewegt sich durch das Haus lautlos, but that sounds less natural and delays the important information about how the mouse moves.

Can durch das be contracted, and if so, how?

Yes. In everyday spoken and informal written German, durch das commonly contracts to durchs. So you can write Die Maus bewegt sich lautlos durchs Haus. In formal contexts, durch das is still perfectly acceptable.

What form is bewegt, and why does it end with -t?

bewegt is the third person singular present-tense form of the regular (weak) verb bewegen. In German, regular verbs add -t for er/sie/es (ich bewege, du bewegst, er bewegt).

Can you say Die Maus bewegt lautlos durch das Haus without sich?

No. Without sich, bewegen needs a direct object (it becomes transitive). If you drop sich, the sentence lacks an object and becomes ungrammatical. If you want a non-reflexive verb, you could choose schleichen: Die Maus schleicht lautlos durch das Haus.

Why is Maus capitalized in Die Maus?

In German, all nouns are capitalized regardless of their position in a sentence. Maus is a noun and therefore always begins with a capital letter.

What gender is Maus, and how do you know?

Maus is feminine, so it takes the article die in the nominative singular: die Maus. Gender often must be memorized, though certain word endings (like -e, -ung, -heit) tend to be feminine.

Are there synonyms for lautlos, and how do they differ?

Yes.

leise (“quietly”) implies low volume but not total silence.
geräuschlos (“without noise”) is very close in meaning to lautlos.
lautlos emphasizes complete absence of sound.
Choose based on nuance: leise if a little sound is okay, lautlos/geräuschlos for total silence.