YOU SAID:

I decided to go either get a burger yesterday

INTO JAPANESE

私は昨日ハンバーガーを買うか

BACK INTO ENGLISH

I buy a hamburger yesterday

INTO JAPANESE

私は昨日ハンバーガーを買う

BACK INTO ENGLISH

I will buy a hamburger yesterday

INTO JAPANESE

私は昨日ハンバーガーを買うつもりです

BACK INTO ENGLISH

I am going to buy a hamburger yesterday.

INTO JAPANESE

私は昨日ハンバーガーを買うつもりです。

BACK INTO ENGLISH

I am going to buy a hamburger yesterday.