uri jibi keoyo.

Literally, 우리 집이 커요 breaks down as:

• 우리 = “our”
• 집 = “house”
• -이 = subject marker
• 커요 = (polite) “is big”

So word-for-word it’s “Our house is big.” Idiomatically, Koreans often use 우리 to mean “my,” so a natural English translation is “My house is big.”

Both -이 and -가 are subject markers, but you choose based on the noun’s ending:

• Use -이 after a noun ending in a consonant (집 ends in ㅂ).
• Use -가 after a noun ending in a vowel.

So 집+-이 → 집이, marking “house” as the subject of the sentence.

This is due to the ㅡ-irregular conjugation:

• The dictionary form is 크다.
• When you add -어요, the stem loses its final ㅡ.
• 크
  • 어요 becomes 커요 (not 크어요).

It’s a regular pattern for all ㅡ-irregular verbs.

커요 is in the polite (존댓말) style known as 하요체. Characteristics:

• Suitable for speaking to acquaintances, colleagues, or strangers you don’t know well.
• It’s more polite than plain form (크다) but less formal than the 존댓말 종결형 (큽니다).

In everyday Korean:

• 우리 doubles as “we/our” and colloquially “my.”
• 나의 집 or 우리의 집 sounds stiff or literary in conversation.
• 우리 집 is natural and warm, especially when referring to one’s own home or family property.

The difference lies in the particle:

• -이 marks the subject (집이 커요 = “The house is big.”)
• -은 marks the topic (집은 커요 = “As for our house, it is big.”)

Using 은 often implies a contrast or sets up a topic for further comment (e.g., “우리 집은 커요, 하지만…​”).