every day是什么意思？怎么使用？

每天是指每隔24小时的一段时间，通常用来表示日常的、重复发生的或者习惯性的事情。它可以作为一个名词或者副词使用。

作为名词时，every day可以指代一天中的所有时间，也可以指代某个特定的日期。：

1. I go to the gym every day. (我每天都去健身房。)

2. Every day is a new opportunity to learn. (每一天都是学习的新机会。)

3. I have been working on this project every day since last month. (自从上个月以来，我每天都在这个项目上工作。)

作为副词时，every day通常放在动词之后，用来修饰动作发生的频率。：

1. She brushes her teeth every day. (她每天都刷牙。)

2. The children play in the park every day after school. (孩子们放学后每天都在公园里玩耍。)

3. He checks his email every day before going to bed. (他睡觉前每天都会查看邮件。)

除了表示日常习惯外，every day还可以用来表示连续不间断的时间段，通常与for连用。：

1. The restaurant has been open for business every day for the past 10 years. (这家餐厅过去10年里每天都营业。)

2. She has been studying English for two hours every day. (她每天都学习英语两个小时。)

此外，every day也可以用来表示平均值或者频率。：

1. The temperature is around 25 degrees every day in summer. (夏天每天的气温大约在25度左右。)

2. On average, she receives 50 emails every day. (平均来说，她每天收到50封邮件。)

总的来说，every day是一个常用的词组，可以用来描述日常生活中发生的事情，也可以用来表示时间段、频率或者平均值。它的使用范围很广泛，在口语和书面语中都可以使用。

例句参考：

1. I try to exercise every day, but sometimes I just don't have the time.

(我尽量每天都锻炼，但有时候就是没有时间。)

2. The sun rises and sets every day, it's a natural cycle.

(太阳每天升起和落下，这是一个自然循环。)

3. He has been traveling for months and hasn't been home every day since then.

(自从几个月前开始旅行以来，他每天都不在家里。)

4. She practices the piano for an hour every day, and her skills have improved significantly.

(她每天练习一小时钢琴，她的技巧有了显著提高。)

5. The store is open from 9 am to 9 pm every day of the week.

(这家商店每天从早上9点到晚上9点都营业。)