錯在那裡?

應該係
I have to come back tomorrow.
had 係過去式
如果你的next day 係明天, tomorrow 會更好
I will come back tomorrow. 亦可以 但意思有Ｄ唔同

I have to come back tomorrow
我明天才能回來
I will come back tomorrow
我明天回來

看你的意思!!

had 系過去式﹐ come back 既過去式系 came back = 唔使用 had
你的句子前段講過去﹐ 後段講未來
i came back from a place yesterday
i have to come back the next day
i have to come back tomorrow

I will come back next day.

因為是next是keyword

應該用will come

I have to come back next day.

I had to come back next day
錯在next day
tomorrow

I have to come back nest day.
I need to come back next day.
I must come back next day.
I should come back next day.
I shall come back next day.
I will come back next day

I have to come back next day

我估係
I will come back tomorrow!
唔知呢

I have to come back next day

I need to come back tomorrow