subject

Chemistry was always my most difficult subject when I was in high school.

(Chinese) 我读高中时，化学一直是我最难的学科。

The students can choose two elective subjects besides their core classes.

(Chinese) 学生们除了核心课程外，还可以选择两门选修科目。

In the sentence 'The cat chased the mouse', the word 'cat' is the subject.

(Chinese) 在句子“猫追老鼠”中，“猫”这个词是主语。

If a sentence has a plural subject, the verb must also be in plural form.

(Chinese) 如果句子的主语是复数，动词也必须使用复数形式。