YOU SAID:

I was looking at these pair of shoes the other day and they were fire

INTO JAPANESE

私は先日これらの靴を見ていましたが、彼らは火でした

BACK INTO ENGLISH

I was watching these shoes the other day but they were on fire

INTO JAPANESE

私は先日これらの靴を見ていましたが、彼らは燃えていました

BACK INTO ENGLISH

I was watching these shoes the other day but they were burning

INTO JAPANESE

私は先日これらの靴を見ていましたが、彼らは燃えていました

BACK INTO ENGLISH

I was watching these shoes the other day but they were burning