watashi wa tsuurogawa no seki ga suki desu.

I like aisle seats.

Breakdown of watashi wa tsuurogawa no seki ga suki desu.

• は: topic particle
• です: to be
• 私わたし: I
• が: subject particle

Questions & Answers about watashi wa tsuurogawa no seki ga suki desu.

What does each word in 私 は 通路側 の 席 が 好き です do grammatically?

Breakdown:

• 私 (わたし) – pronoun I / me
• は – topic particle: marks 私 as the topic (as for me / speaking about me).
• 通路側 (つうろがわ) – noun meaning aisle side.
• の – linking/possessive particle; here it turns 通路側 into an adjective-like modifier of 席: aisle‑side seat.
• 席 (せき) – noun meaning seat.
• が – subject/marked item particle; with 好き, it marks the thing that is liked.
• 好き (すき) – na‑adjective meaning liked / fond.
• です – polite copula, like is / am / are, making the sentence polite.

So the structure is roughly:
[As for me], [aisle‑side seat] is liked. → I like aisle seats.

Why are both は and が used in the same sentence? Which one is the subject marker?