いつ来るか

when ... will come

→ いつ
phrase Rare #32,230
when ... will come Used to ask or refer to the time when someone or something will come. The か marks an embedded question, as in 彼がいつ来るか分かりません (I don't know when he will come).
JA: 次の電車がいつ来るか知っていますか。
EN: Do you know when the next train will come?

私はジェーン今度いつ来るか心配です

I'm worried about when Jane will come next.

トムいつ来るかメアリー伝えました

Did you tell Mary when Tom is coming?

彼がここへいつ来るか分かりません

I don't know when he'll come here.

彼がいつ来るかご存知ですか

Do you know when he will arrive?

サンタクロースいつ来るか

I wonder when Santa Claus will come.