YOU SAID:

Some times, when I am tired I go to sleep, but I can't go to sleep if i'm not tired, so when I am not tired I don't go to sleep, because I am unable to, as I am not tired.

INTO JAPANESE

時には疲れて眠りますが、疲れていなければ寝ることができないので、疲れていないときは眠れません。疲れていない。

BACK INTO ENGLISH

- Come along. - I'm not tired.

INTO JAPANESE

- 疲れていない！

BACK INTO ENGLISH

- Come along. - I'm not tired.