YOU SAID:
I'd like to eat a pizza with pineapples
INTO JAPANESE
私はパイナップルでピザを食べたい
BACK INTO ENGLISH
I want to eat pizza in pineapple
INTO JAPANESE
私はパイナップルでピザを食べたい
BACK INTO ENGLISH
I want to eat pizza in pineapple
That didn't even make that much sense in English.