Is 「出ちゃいけません」 short for 「出ちゃってはいけません」?


The sentence in question:

> 道の外側に出ちゃいけません！

While it is obvious what it means, I am wondering how precisely it is
constructed grammatically.

The textbook way of expressing "must not do" using いけない is:

[て-Form] は いけない

So going by that I would construct it as follows:

出る → 出ちゃう → 出ちゃって → 出ちゃってはいけません

So I assume 「出ちゃいけません」 is simply a shortened form of this grammar.

Is that correct?

If yes, is this common?

If no, how is 「出ちゃいけません」 made up grammatically?




No, short for 出ちゃってはいけません would be 出ちゃっちゃいけません. ～ては itself contracts to ～ちゃ
(compare ではない and じゃない), so 出ちゃいけません is a contracted form of 出てはいけません. This
kind of contraction is extremely common.




No, short for 出ちゃってはいけません would be 出ちゃっちゃいけません. ～ては itself contracts to ～ちゃ
(compare ではない and じゃない), so 出ちゃいけません is a contracted form of 出てはいけません. This
kind of contraction is extremely common.

