There are two tenses in English – past and present.

英語里有兩種時態—過去時和現在時。

The past tense in English is used：

英語里過去時用于：

to talk about the past

談論過去

to talk about hypotheses – things that are imagined rather than true.

談論假設

for politeness.

基于禮貌

There are four past tense forms in English：

We use these forms：

to talk about the past：

He worked at McDonald’s. He had worked there since July.

He was working at McDonald’s. He had been working since July.

to refer to the present or future in conditions：

He could get a new job if he really tried.

If Jack was playing they would probably win.

and hypotheses：

It might be dangerous. Suppose they got lost.

I would always help someone who really needed help.

and wishes：

I wish it wasn’t so cold.

In conditions， hypotheses and wishes， if we want to talk about the past， we always use the past perfect：

在條件狀語從句、虛擬語氣以及表祝愿時，我們在談論過去時，經常使用過去完成時。

I would have helped him if he had asked.

It was very dangerous， What if you had got lost？

I wish I hadn’t spent so much money last month.

We can use the past forms to talk about the present in a few polite expressions：

在一些禮貌的表達中，我們用過去式來談論現在的事情。

Excuse me， I was wondering if this was the train for York.

I just hoped you would be able to help me.

（實習編輯：于曉偉）