be动词与介词"with"搭配时，be动词的单复数形式取决于"with"前面的主语。具体规则如下：
单数主语
当"with"前面是单数名词或不可数名词时，be动词用"is"。例如：
- The manager is in charge of the project.
- The weather is very cold today.
复数主语
当"with"前面是复数名词或第二人称（you）时，be动词用"are"。例如：
- The students are busy with their homework.
- We are going to the park with our friends.
补充说明
若"with"连接两个并列的主语，需使用"就近原则"，即根据离be动词最近的主语确定单复数。例如：
The teacher, with the students, is organizing the meeting. [is]
The teacher and the students are preparing for the exam. [are]
常见搭配
be angry with（对…生气）
be busy with（忙于…）
be concerned with（关心）
be content with（对…满意）
通过以上规则，可以灵活处理包含"with"的复杂句型。