倒装句分全倒装句和半倒装句。
一. 全倒装: 主语与谓语交换位置不需任何助动词, 叫全倒装。
全倒装有以下三种情况:
1.当here, there, out, in, up, down等副词放在句首时, 句子需全倒装。
2.方位状语在句首。
3.直接引语在句首, 这种情况可倒装也可不倒装。
二.半倒装: 主语与谓语的助动词交换位置称半倒装, 有以下数种情况:
1.否定意义的词在句首, 句子半倒装。
2.几对并列连词如not only、but also, hardly、when等连接两个并列句, 连词在句首, 前句半倒装, 后句不倒装。
3.only在句首强调状语, 主句半倒装。
4.so、that句型, so在句首时, 主句倒装, that从句不倒装。
5.省略了if的虚拟条件句。
1.时间介词。
例如：at表示在某时刻、时间、阶段。
例句：My cousin joined the army at fifteen。
翻译：我表哥十五岁参的军。
2.表示做某事的方法、手段的介词。
例句：She cut the cake with a knife。
翻译：她用刀切开了蛋糕。
3.表示空间的介词。
例句：Some kids are playing in the yard and others are playing in the room。
翻译：有些孩子在院子里玩，其他则在房间里玩。
（一）一般现在时：
I learn English everyday.
He learns English everyday.
（二）一般过去时
I learned/learnt English yesterday.
He learned/learnt English yesterday.
（三）一般现在进行时
I am learning English now.
He is learning English now.
（四）一般过去进行时
I was learning English at 3:00 yesterday .
He was learning English at 3:00 yesterday .
（五）一般将来时
1.be going to 表将来
I am going to learn English tomorrow.
He is going to learn English tomorrow.
Will表将来
I will learn English tomorrow.
He will learn English tomorrow.
（六）一般现在完成时
Since➕时间点
I have (already) learnt/learned English since I was five years old.
He has (already) learnt/learned English since he was five years old.
for ➕一段时间
I have （already) learnt/learned English for ten years.
He has （already) learnt/learned English for ten years.