be busy with和be busy for 都有“忙于做……”的意思 。
1. be busy with sth = be busy doing sth 忙于做某事
2. be busy for sth 为……而忙
如：
1). He is busy with his homework.
=He is busy doing his homework .
他忙于做作业。
2). I am busy for studying English recently.
我最近在忙着学英语。
be busy with
1、Be busy with I am busy with my homework.
我不想让我的双手因不必要的事情而更加忙碌。
2、By the end of this month we will be busy with company's salary report.
这个月的月底我们又将忙于做出公司职工的工资报表。
3、He pretended to be busy with some work.
他假装忙着什么事。
4、% 1 cannot answer your call right now. This person may be busy with another call.
%1无法立即回答您的呼叫。他可能正忙于另一个呼叫。
5、Owing to the fierce competition, he was compelled to be busy with his work all day long.
由于竞争激烈，他不得不整日忙于工作。
be busy for
1、You, he and I will be busy for a while.
你、我还有他都将要忙上一阵子了。
2、Will you be busy for lunch tomorrow?
明天你有来吃午饭吗？
3、Today was a busy day again! I will be busy for a week or so
今天又忙了一天！还要接着再忙一周
4、They would be busy for a long time to come, but actions triggered by computers were far ahead of them now.
他们得忙上很长一段时间才来，但由计算机开始的行动已大大地走在了他们的前面。
5、We will be very busy for the next three or four days.
未来的三、四天，我们将会很忙。