Мой друг живёт в соседнем доме.

In Russian, every noun has grammatical gender. Друг is a masculine noun, so it takes the masculine form of my, which is мой.

• мой друг – my (male) friend
• моя подруга – my (female) friend (here подруга is feminine, so you use моя)

So:

• мой = my (masculine)
• моя = my (feminine)
• моё = my (neuter)
• мои = my (plural)

Живёт is:

• 3rd person singular (he/she/it)
• present tense
• imperfective aspect
• verb: жить (to live)

It covers both English meanings:

• My friend lives in the neighboring house.
• My friend is living in the neighboring house.

Russian doesn’t separate “lives” vs “is living” in the present the way English does; живёт can mean both, context decides.

Because the sentence describes location, not movement.

With в:

• Where? (location) → в
  • prepositional case
    
    • в соседнем доме – in the neighboring house (static location)
• Where to? (direction) → в
  • accusative case
    
    • в соседний дом – into the neighboring house (movement, going there)

In Мой друг живёт в соседнем доме, your friend already lives there, so it’s location → prepositional case: соседнем доме.

Соседний is an adjective meaning neighboring / next-door.

Adjectives in Russian change form to match case, number, and gender of the noun. Here:

• Nominative masculine singular: соседний дом – neighboring house
• Prepositional masculine singular: в соседнем доме – in the neighboring house

So the pattern is:

• соседний → соседнем (prepositional, masc. sing.)
• дом → доме (prepositional, masc. sing.)

Both the adjective and noun change when used after в for location.

The base form is дом (house).

In в соседнем доме, дом is in the prepositional case (answering “where?” after в), and masculine nouns like this usually take -е:

• Nominative: дом – house
• Prepositional (location): в доме – in the house

Дома is a different word:

• дома (adverb) = at home
  
  • Он дома. – He is at home.

So:

• в доме – in the house (inside a specific house)
• он дома – he is at home (general location “at home”)

Yes. Russian word order is relatively flexible, and different orders change the emphasis, not the basic meaning.

• Мой друг живёт в соседнем доме.
  Neutral; focus on who and where he lives.

• В соседнем доме живёт мой друг.
  Starts with the location, often used when the place is already in focus:
  “In the neighboring house lives my friend.” (emphasis on who lives there.)

Grammatically, both are correct. In normal speech, both sound natural, with slightly different information focus.

Друг is:

• grammatically masculine
• usually means friend (not necessarily romantic)

For people:

• друг – male friend
• подруга – female friend

For romantic partners:

• мой парень, мой молодой человек – my boyfriend
• моя девушка – my girlfriend

So мой друг живёт в соседнем доме is normally understood as:

• “My (male) friend lives in the neighboring house”, not “My boyfriend …”

You need plural forms:

• Мои друзья живут в соседнем доме.

Changes:

• мой друг → мои друзья
  
  • друг (friend) → друзья (friends) – irregular plural
  • мой → мои (plural “my”)
• живёт (he/she lives) → живут (they live)

Russian has no articles (no “a/an” or “the”).

Whether you mean:

• a neighboring house or
• the neighboring house

is decided by context, not by a separate word.

So в соседнем доме can be:

• in a neighboring house
• in the neighboring house

depending on what has already been mentioned or is obvious from the situation.

All can express the idea of “next door / nearby,” but they work differently:

• в соседнем доме – in the neighboring house (very concrete: specifically in the house next to yours)
• рядом – nearby / next to (more general)
  • Мой друг живёт рядом. – My friend lives nearby.
• по соседству – in the neighborhood / close by / next door-ish
  • Мой друг живёт по соседству. – My friend lives nearby / in my neighborhood.

If you want the most literal “in the house next door”, в соседнем доме is the clearest.

The correct full spelling here is живёт, with ё.

• ё is pronounced “yo” (like yo in “yoga”) and is always stressed.
• So живёт sounds like [ж-и-в-йО-т] – “zhi-VYOT”.

In everyday writing, native speakers often omit the two dots and write живет, but they still pronounce it живёт.
For learners, it’s better to keep the dots on ё until you feel confident with stress and pronunciation.

Stresses (marked with ´):

• Мой – [мой] (stress on the only syllable)
• друг – [друг] (one syllable)
• живёт – [живЁт] – stress on -вёт
• в – [в] (very short)
• соседнем – [сасЕд-н’ем] – stress on -сед-
• доме – [дО-м’е] – stress on до-

So roughly:

• Мой друг живёт в соседнем доме.
  [Moi drug zhivYOT f saSYED-n’em DÓ-m’e]

The main sentence stress usually falls on живёт and/or соседнем доме, depending on what you’re emphasizing.