我星期六要返學校練波 英文

因唔知你想點講,比幾個example你

I have to attend the (eg.football) training on Saturday at school

I go school for (eg.football) training on Saturday

I go school on Saturday for the (eg.football) training

3個都ok,英文好多講法都ok,但1係比較formal,同老師/長輩講或交代比較合適,2同3就較causel
tense就隨你個case而改,未發生就用以上,
指明黎緊果個星期6就係saturday前加(on the coming),
eg.I go school for (eg.football) training every Saturday
個個星期6都要就加(every),
eg.I go school on the coming Saturday for the (eg.football) training
發生左講返之前ga事就(go->went)(have to->was)同埋動詞轉過去式
eg.I was attended the (eg.football) training on Saturday at school

I have to go for a soccer training course at the school on Saturday.

我星期六要返學校練波
I have to attend a soccer (or basketball) training course the coming Saturday at school.

I need to go to school to practice the football/basketball/table tennis on Saturday.