YOU SAID:

if there is a chair then I will eat it because I am liking chairs this few decades

INTO JAPANESE

椅子があれば私はそれを食べるでしょう

BACK INTO ENGLISH

If there is a chair I will eat it

INTO JAPANESE

椅子があればそれを食べるつもりです

BACK INTO ENGLISH

I will eat it if I have a chair

INTO JAPANESE

椅子があればそれを食べる

BACK INTO ENGLISH

Eat it if you have a chair

INTO JAPANESE

あなたが椅子を持っているならそれを食べなさい

BACK INTO ENGLISH

Eat it if you have a chair