Ich schütte Wasser in den Eimer.

I pour water into the bucket.

Breakdown of Ich schütte Wasser in den Eimer.

• das Wasser: the water
• ich: I
• in: into
• den: the; (masculine, accusative)

Questions & Answers about Ich schütte Wasser in den Eimer.

Why is it in den Eimer and not in dem Eimer?

German uses two-way prepositions like in with either accusative or dative:

• Accusative = movement / change of location
  • Ich schütte Wasser in den Eimer.
    → The water is moving into the bucket.
• Dative = location / no movement
  • Das Wasser ist in dem Eimer. (usually contracted to im Eimer)
    → The water is already in the bucket and stays there.

Because the sentence describes pouring into (a change of location), in takes the accusative, so you get den Eimer, not dem Eimer.

Why does Eimer use den here?

Eimer is a masculine noun:

• der Eimer – nominative singular
• den Eimer – accusative singular

The phrase in den Eimer uses the accusative (see previous answer), and masculine accusative singular always takes den, so we say in den Eimer.

Do I need an article with Wasser? Why is it just Wasser and not das Wasser?