

Mein Bruder ist dreizehn Jahre alt.
[ˈmaɪ̯n ˈbruːdɐ ˈɪst ˈdraɪ̯tseːn ˈjaːrə ˈalt.]
My brother is thirteen years old.
Ich wohne in Zimmer dreizehn.
[ˈɪç ˈvoːnə ˈɪn ˈtsɪmɐ ˈdraɪ̯tseːn.]
I'm staying in room thirteen.
Wir sind dreizehn Leute in der Klasse.
[ˈviːɐ̯ ˈzɪnt ˈdraɪ̯tseːn ˈlɔɪ̯tə ˈɪn deːɐ ˈklasə.]
There are thirteen of us in the class.
"dreizehn" is in the lesson "Numbers" (Level 3), along with 19 other useful words. LinDuo has 180 topic lessons like this one, 2,375 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.