YOU SAID:

I dont think ive ever seen one that small before

INTO JAPANESE

私はこれまでに小さいことを見たことがあるとは思わない

BACK INTO ENGLISH

I do not think I have seen small things so far

INTO JAPANESE

私はこれまで小さなことを見たことがないと思います

BACK INTO ENGLISH

I think that I have never seen a small thing so far

INTO JAPANESE

私はこれまで小さなことを見たことがないと思います

BACK INTO ENGLISH

I think that I have never seen a small thing so far