Question

The teacher with his student _______ going swimming this afternoon.

A. are B. am C. is

为什么选C

Answer 1

在sb with sb 作主语的结构中，谓语动词的选择根据就远原则，即看with前面的名词或代词的单复数来判断，而非看with后面的接近谓语动词的那个名词或代词判断，例如：1.My friends with I often go to play ball after class.2.I with my mother go to see my grandpa once a week.3.Tom with his mother is going to have a trip this weekend.4.I with my sister am going to do some shopping this aftenoon.
所以选择c 看the teacher判断谓语动词

Answer 2

c

主语是the teacher 尽管后面跟上了介词短语，意思上是复数，但谓语与主语一致。

Answer 3

with his student，可以忽略不看，即可以去掉，意为‘和他的学生’。
整个句子的主语是 ‘The teacher‘
主语是单三人，谓语当然选is

Answer 4

因为with是伴随主语，真真的主语是 the teacher
如果with改为and，就填are

Answer 5

with 是介词，介词后跟的名词his student 是宾语，所以这里的主语是the teacher,因此，谓语动词自然是用于第三人称单数的is 了。