初中英语八大时态的基本结构如下：

一般现在时

结构：主语 + be （am/is/are） + 表语；主 + 谓（do） + 宾

例句：

I am a worker.

She goes to school every day.

They often play football on weekends.

现在进行时

结构：be （am/is/are） + doing

例句：

I'm waiting for you.

She is reading a book.

They were having dinner at 6 o’clock.

一般过去时

结构：be （was/were） + 表语；主 + did + 宾语

例句：

He was a doctor two years ago.

I went to the zoo yesterday.

They stood there just now.

过去进行时

结构：be （was/were） + doing

例句：

When I got to the top of the mountain, the sun was shining.

They were playing basketball last night.

一般将来时

结构：be going to do

例句：

They are going to climb mountains this weekend.

I will travel to Japan next year.

She will be a doctor in the future.

现在完成时

结构：主 + have/has + 过去分词

例句：

I have finished my homework.

By the end of last year, they had built 500 houses.

She has lived here since last year.

过去完成时

结构：主 + had + 过去分词

例句：

By the time we arrived at the station, the train had already left.

They had finished their homework before going out.

过去将来时

结构：was/were + going to do

例句：

She was going to buy a new dress next week.

They were planning to visit their grandparents last summer.

这些时态在初中英语中非常重要，掌握它们有助于更好地表达时间和状态。建议通过大量练习和实际应用来巩固这些时态的用法。