Looking up...
私といっしょに来てください。
Please come with me.
in the same place or time; together
子供といっしょに公園に行きました。
I went to the park with my child.
彼といっしょに住んでいます。
I live with him.
Used with に to indicate accompaniment (e.g., 彼といっしょに 'with him').
the same; identical
私たちの意見は全くいっしょです。
Our opinions are exactly the same.
Often used in comparisons or statements of agreement.
used to emphasize shared experience or state
彼といっしょに旅行に行きたいです。
I want to travel with him.
Can imply emotional or experiential togetherness.
Use いっしょ in casual speech. In writing or formal settings, prefer 共に (ともに) for 'together' or 同じ (おなじ) for 'the same'.
When meaning 'together with someone,' attach に to いっしょ (e.g., 彼といっしょに 'with him').
From Middle Japanese 一所 (いっしょ, issho), combining 一 (いち, ichi, 'one') + 所 (しょ, sho, 'place'). The sense of 'together' emerged from the idea of being in the same place.
Used in casual speech; more formal alternatives include 共に (ともに) or 同じく (おなじく). When used as an adjective (e.g., 同じ), it often replaces いっしょ in formal contexts.