途中で/途中に（とちゅうで/とちゅうに）

About

～途中とちゅう may be combined with either the に or で particle, and has two main usages:

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  ① "On the way to (location)"

E.g. 図書館としょかんに行いく途中とちゅうにあるカラオケが、なくなったらしい。 "Apparently the karaoke place that was on the way to the library is gone."

E.g. ここに来くる途中とちゅうに、美味おいしそうなラーメン屋やがあった。 "There was a tasty-looking ramen place on the way here."

② "In the middle of (action)"

E.g. スペイン語ごのコースを、途中とちゅうでやめてしまった。 "I quit my Spanish course partway through."

E.g. 途中とちゅうで諦あきらめたら、それまでの努力どりょくが無駄むだになる。 "If you give up in the middle, your efforts up to that point will be wasted."

If a ～途中とちゅう statement deals with existence (i.e. uses ある・いる), に should be used.

If a ～途中とちゅう statement deals with an action that is quit/ends/is altered partway through, で should be used.

In situations where either で or に may be used (general "X happens in the middle of Y" statements), で places more emphasis on what happens while に places more emphasis on when it happens.

で・に may be omitted from 途中とちゅう in spoken, casual scenarios. Particles cannot be omitted from 「途中とちゅうにある」 constructs, or when 途中とちゅうで is used to describe stopping/quitting/altering an action part way.

Summary

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  ～途中とちゅう may be combined with either the に or で particle, and has two main usages: ① "On the way to (location)", ② "In the middle of (action)"

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  If a ～途中とちゅう statement deals with existence (i.e. uses ある・いる), に should be used

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  If a ～途中とちゅう statement deals with an action that is quit/ends/is altered partway through, で should be used