四年级下册英语常用句子表达法包括：
询问地点:
Where's the teachers' office？
It's on the second floor.
确认地点:
Is this the teachers' office？
No, it isn't. The teachers' office is next to the library.
询问时间:
What time is it？
It's 6 o'clock. It's time for dinner.
日常活动:
Time to go home, kids.
It's time to get up.
天气情况:
Can I go outside now？
Yes, you can. / No, you can't. It's cold outside.
What's the weather like in New York？
It's rainy.
自我介绍:
What's your name？
My name is... I'm from... I am... years old.
询问喜好:
What's your favorite subject？
My favorite subject is English.
询问能力:
Can you speak English/Chinese？
Yes, I can. / No, I can't.
询问衣物:
Whose coat is this？
Whose pants are those？
询问颜色:
What color is it？
It is... （color here）
以上句子表达法涵盖了四年级下册英语课程中常见的交流场景，适合学生学习和使用。