英语的12种时态结构如下：
简单现在时
结构：主语 + 动词原形
例句：I eat breakfast every morning.
现在进行时
结构：主语 + am/is/are + 现在分词
例句：They are watching TV now.
现在完成时
结构：主语 + have/has + 过去分词
例句：I have finished my homework.
简单过去时
结构：主语 + 动词的过去式
例句：She visited the museum last Saturday.
过去进行时
结构：主语 + was/were + 现在分词
例句：He was reading a book when I arrived.
过去完成时
结构：主语 + had + 过去分词
例句：By the time I arrived, they had already eaten dinner.
一般将来时
结构：主语 + will + 动词原形
例句：I will travel to Japan next year.
将来进行时
结构：主语 + will be + 现在分词
例句：She will be working at 8 pm tonight.
将来完成时
结构：主语 + will have + 过去分词
例句：By the end of this year, I will have saved enough money for a new car.
现在完成进行时
结构：主语 + have/has been + 现在分词
例句：They have been studying for hours.
过去完成进行时
结构：主语 + had been + 现在分词
例句：She had been working at the company for five years before she got the promotion.
过去将来完成时
结构：主语 + would have + 过去分词
例句：If I had known about the party, I would have attended it.
这些时态结构涵盖了英语中描述不同时间发生的动作和状态的各种情况。掌握这些时态有助于更准确地表达时间和逻辑关系。建议通过大量的阅读和写作练习来巩固这些时态的使用。