四年级下册英语句子主要涵盖日常交流、学校生活、自然现象等主题，以下是部分典型例句分类整理：

一、日常交流类

1. 问候与时间

Hello! How's your day？

It's 9 o'clock. It's time for school.

Good morning/afternoon!

2. 基本疑问句

Where is the teachers' office？

Is this your book？

Can I go outside now？

二、学校生活类

1. 课程与活动

It's time for English class.

What's the weather like in New York？

The students are playing basketball on the playground.

2. 学校设施

This is the computer room.

We have a library.

The library is next to the teachers' office.

三、自然与生活类

1. 天气描述

It's sunny today.

It's raining in London.

The weather is warm in spring.

2. 动物与植物

This is a cat.

These are carrots.

The sky is blue.

四、行为与状态类

1. 能力与喜好

I can swim.

I like reading books.

She is a kind teacher.

2. 形容词与副词

The flowers are beautiful.

He is very cool.

It's very old.

注：以上例句综合了教材中的常见句型结构，实际教学中需结合具体语境进行拓展。建议通过对话练习、角色扮演等方式巩固句型应用能力。