▲要用英语表示“上厕所”，是用 go to the toilet 而不是 go to toilet，即要用冠词（与 go to school, go to church 等不一样）。如：

Mummy, I need to go to the toilet! 妈妈，我要上厕所！

It’s going to be a long journey, kids, so if you want to go to the toilet do so now.  孩子们，我们要作长途旅行，所以如果要上厕所现在就去。

Then I went to the toilets and, horror of horrors, discovered that my zip had been undone.  最糟糕的是，当我上厕所的时候发现裤子的拉链一直开着。

▲以下表达中的 toilet 前也要用冠词。如：

He had to join the queue for the toilets. 他得排队等候上厕所。

He went in and joined the queue for the toilets. 他走进去排队上厕所。

I was on (= using) the toilet when the phone rang. 电话铃响时我正在上厕所。

Do you need the toilet right now or can you hang on for a while? 你现在就要上厕所还是能再等一会儿呢？

▲附其他相关表达：

1. 用 bathroom 表示：

I need to go to the bathroom. 我要上厕所。

I really need to go to the bathroom (=use a toilet). 我很想上厕所。

Although he had been treated with antibiotics, he went to the bathroom repeatedly. 虽然他已经服用了抗生素，但他还是不停地上厕所。

2. 在非正式场合用loo：

I need to go to the loo. 我要上厕所。

I’m bursting to go to the loo! 我急着想上厕所！