I have difficulty understanding the grammar.

我理解语法有困难。

同一单元的其他句子

• The students are listening to the teacher in the classroom.学生们正在教室里听老师讲课。
• What subjects do you study at school?你在学校学习哪些科目？
• I have a lot of homework to do tonight.我今晚有很多作业要做。
• Don't forget to bring your textbooks to class.别忘了把课本带到课堂上来。
• The library is open from nine to five on weekdays.图书馆在工作日从九点到五点开放。