定语从句改非谓语
定语从句改成非谓语的方法如下：
表示主动，正在进行的动作的时候，可以用现在分词来改写。如：
I know the girl who is talking to the teacher.
I know the girl talking to the teacher.
我认识正在和老师说话的那位女孩。
The woman who is waving from the window is my mom.
The woman waving from the window is my mom.
在窗户那边挥手的人是我妈妈。
2. 表示被动，已经完成的动作的时候，用过去分词来改写，如：
Shirts which are made of silk are very expensive.
Shirts made of silk are very expensive.
丝织的衬衫很贵。
I like the building which was designed by Mr. Wu.
I like the building designed by Mr. Wu.
我喜欢这栋被吴先生设计出来的大楼。
3. 表示将来的动作，用动词不定式来改写，如：
The problem which is going to be discussed tomorrow is our quarterly meeting.
The problem to be discussed tomorrow is our quarterly meeting.
明天要讨论的问题是我们的季度会议。
4. 表示正在被进行的动作，用现在分词的被动式来改写。如：
The problem which is being discussed now is our quarterly meeting.
The problem being discussed tomorrow is our quarterly meeting.
现在正在讨论的问题是我们的季度会议。
定语从句转换成非谓语动词以及转换时应注意的事项：
1定语从句转换成不定式
1.1定语从句转换成不定式“to do”。
定语从句的谓语动词是将来时或含有情态动词或含有序数词the next， the last等时，该定语从句转换为不定式“to do”.
（1）The plane which will arrive is from Hubei.
→The plane to arrive is from Hubei。
（2）The students will go to a party that will be held in our class at 7：45.
→The students will go to a party to be held in our class at 7：45.
（3）He was the first boy who came to school.
→He was the first boy to come to school.
1.2定语从句可转换成为“介词+关系代词或副词+不定式”。 “介词+关系代词”引导的定语从句和“介词+关系代词或副词+不定式”充当的定语，可以相互转换。被这种定语修饰的名词往往在逻辑上充当不定式动作的地点、时间或工具。例：
（1）She wanted a room in which she could do her homework.
→She wanted a room in which to do her homework.
（2）She had only a pen with which she can write.
→She had only a pen to write with.或She had only a pen with which to write.
注：定语从句转换成“介词+ 关系代词+不定式”时，此时的不定式一定是及物动词，如是不及物动词，则需在动词后面加上相应的介词。这个介词可提前到关系代词前面，也可留在句尾。前者是正式说法后者是非正式说法。而且上例中动词不定式与句子主语之间存在着逻辑上的主谓关系，否则就不能简单地把作定语的不定式都变成此结构。
“He is looking for a place for his friend to live in”这句话。我们就不能将句中的a place for his friend to live in改为a place to live in或a place in which to live。
2定语从句可以转换为分词（短语）
当以关系代词引导的定语从句作定语，且关系代词在从句中作主语时，我们可以将定语从句转换成分词（短语）。
2.1定语从句可以转换为现在分词（短语）
如果定语从句的谓语是主动语态，且发生的时间与主句的谓语所表示的动作所发生的`时间同时，此时可以将定语从句转换成现在分词短语）。
（1）Have you ever talked to the girl who is dancing to music over there？ →Have you ever talked to the girl dancing to music over there？
（2） The question that is being discussed is about how to improve living conditions.
→The question being discussed is about how to improve living conditions.
2.2定语从句可以转化为过去分词（短语）
如定语从句的谓语是被动语态，或是“系动词+过去分词（表语）”结构，且从句的谓语动词所表示的动作或状态是在主句的谓语之前发生或无明确的时间。此时，我们可以将定语从句转换成过去分词（短语）。有时定语从句谓语虽然是主动语态.但它表示的动作在主句谓语之前就已经完成，这时我们可以将定语从句转换成过去分词（短语）。
（1）The report that was made yesterday will be discussed today.
→The report made yesterday will be discussed today.
（2）The dictionary which my mother bought for me is very useful.
→The dictionary bought for me by my mother is very useful.
但以下几种情况，一般不可把定语从句转换为分词（短语）。
1.虽关系代词作定语从句的主语，但如从句的谓语中含有情态动词，则不能转换成分词（短语）。
Those who must hand in their homework before 12 are studying hard now. 此句不宜转成：Those handing in their homework before 12 are studying hard now.
2.如关系代词在从句中作主语，且从句谓语是完成时的主动语态，一般不转换成分词（短语）。
例：The engineer who has finished his design is about to visit Hawaii.此举不宜转化为： The engineer having finished his design is about to visit Hawaii.
3.以关系代词which或as引起的非限制性定语从句，当关系代词指的是前面整个句子，将这个非限制性定语从句转换成分词（短语），其逻辑主语是其前面或后面的整个句子，但分词在这个在句子里结果状语。
例 ：The boy's parents died， which left him an orphan.
→His parents died， leaving him an orphan.
