tomodachi wa senkou, watashi wa koukou da.

My friend plays first, and I play second.

Breakdown of tomodachi wa senkou, watashi wa koukou da.

• は: topic particle
• 私わたし: I
• 友とも達だち: friend
• だ: to be

Questions & Answers about tomodachi wa senkou, watashi wa koukou da.

What do 先攻 and 後攻 mean exactly? Are they common words?

Yes. 先攻（せんこう） means going first or taking the first turn, and 後攻（こうこう） means going second or taking the second turn.

These are especially common in:

• games
• sports
• matches
• card games
• any situation where turn order matters

So this sentence sounds very natural in a game or match context.

Why is は used twice?

The two は particles mark a contrast:

• 友達は先攻
• 私は後攻だ

This gives the sense of as for my friend..., as for me... or my friend goes first, while I go second.

Using は twice is very common when comparing or contrasting two things. Here, it clearly sets up the two roles against each other.

Why isn’t が used instead of は?