你给他写一封信。

You write him a letter.

士兵每周给家人写一封信。

The soldier wrote a letter to his family every week.

此时此刻，我正在写一封信。

At this very moment, I am writing a letter.

他正在写一封信。

He is in the process of writing a letter.

我可以每周给他写一封信。

I can write to him once a week.

我们可以一个月给对方写一封信。

We can write to each other once a month.

我本可以用瓶子写一封信，但等待答案需要十年，现在只需点击一下按钮。

I could have written a letter in a bottle but waiting for the answer would take a decade, now it's just a click of a button.

我本可以用瓶子写一封信，但等待答案需要十年，现在用电子邮件只需点击一下按钮。

I could have written a letter in a bottle but waiting for the answer would take a decade, now with email it's just a click of a button.

比尔在写什么? 他在写一封信。

What is Bill writing? He is writing a letter.

苏西：我在写一封信。

Susie: I'm writing a letter.