YOU SAID:

My pants are too tight, I can't sit still.

INTO JAPANESE

私のズボンがきつすぎる、私はまだ座ることができない。

BACK INTO ENGLISH

My pants are too tight, I can not sit yet.

INTO JAPANESE

私のズボンはきつすぎるので、まだ座ることはできません。

BACK INTO ENGLISH

My pants are too tight for me to sit yet.

INTO JAPANESE

私のズボンは私がまだ座るにはきつすぎる。

BACK INTO ENGLISH

My pants are too tight for me to sit still.

INTO JAPANESE

私のズボンは私が静止するのにはきつすぎる。

BACK INTO ENGLISH

My pants are too tight for me to stand still.

INTO JAPANESE

私のズボンは私が静止するにはきつすぎる。

BACK INTO ENGLISH

My pants are too tight for me to stand still.