YOU SAID:

i have misplaced my pants

INTO JAPANESE

私は私のズボンを間違って配置している

BACK INTO ENGLISH

I have placed my pants by mistake

INTO JAPANESE

私は誤ってズボンを着てしまった

BACK INTO ENGLISH

I accidentally put on my pants

INTO JAPANESE

私は誤ってズボンを着ました

BACK INTO ENGLISH

I accidentally put on my pants