Learn Russian: Я живу в доме три.

When a number acts as a label or ID (like a house number, bus number, or room number), it stays in its basic dictionary form. So even though дом changes to доме because of the preposition в, три stays exactly as три.

Why is there an -е at the end of дом?

The word for house is дом. When you talk about location using в (in), you must use the prepositional case. For most masculine words like дом, this means adding an -е to the end, making it доме.

How do I pronounce the letter в before доме?

In Russian, short prepositions like в merge with the next word when speaking. You pronounce it as one single block: вдоме. Because д is a voiced sound (your vocal cords vibrate), the в keeps its normal V sound.

Why does the verb for live end in -у?

The dictionary form of the verb to live is жить. Like most Russian verbs, it changes its ending depending on who is doing the action. For Я (I), the ending becomes -у, creating живу.