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two persons; two people; pair; couple
二人で公園を歩いていた。
The two were walking in the park.
二人の意見が合わなくて困った。
The two couldn't agree and that was a problem.
二人きりで静かな夜を過ごすのもたまにはいい。
It's nice to spend a quiet evening alone together once in a while.