YOU SAID:

My granny ate some grapes but caught fire afterwards

INTO JAPANESE

おばあさんはぶどうを食べたが、その後火事になった

BACK INTO ENGLISH

The grandmother ate grapes, but then caught fire

INTO JAPANESE

おばあさんはぶどうを食べたが火がついた

BACK INTO ENGLISH

The grandmother ate grapes, but they caught fire.

INTO JAPANESE

おばあさんはぶどうを食べましたが、火がつきました。

BACK INTO ENGLISH

The old woman ate grapes, but they caught fire.

INTO JAPANESE

おばあさんはぶどうを食べましたが、火がつきました。

BACK INTO ENGLISH

The old woman ate grapes, but they caught fire.