YOU SAID:

after a while this sentence wont make sense

INTO JAPANESE

しばらくしてからこの文が意味をなさない

BACK INTO ENGLISH

This sentence does not make sense after a while

INTO JAPANESE

この文はしばらくしても意味をなさない

BACK INTO ENGLISH

This sentence does not make sense for a while

INTO JAPANESE

この文はしばらくは意味をなさない

BACK INTO ENGLISH

This sentence does not make sense for a while