英文字後面+that

所有英文句子都一定S+ V+O, 一句句子不能多過一個動詞, 除非加上連接詞(或用Gerund , to-infinitive), 如I wish that you will be more handome each year. I wish 是主句, 而that clause 是名詞子句, that 後面的是代表一件事情, 故是名詞子句.

但是, 有一條文法規例定明, 若果that 後面是sub(名詞, 或代名詞)的話,THAT 便可以唔要, 睇你個CASE, 由於that 後面接you, 是主詞的代名詞, 因此其實可以唔要的, 但我常同學生講 , 若果你分唔清便保留that 吧, 較保險.

咁你問我, 有沒有一些情怳一定要保留THAT 呢, 有.

I think that (that後面沒有代名詞, 亦沒有名詞, 故要保留) is great.
若說成I think is great便大錯特錯了.

There is no reason and it is optional in this case to add "that".