一、“名词 + 不定式”中,如果这个名词与不定式有逻辑关系——主谓、动宾或动状——时,不定式就是后置定语.这种情况下,不定式可以用“关系词 + 主语 + will/can/be able to + 动词”改写为定语从句,如：
1、There are many things to do （things 和 to do 之间是动宾关系）,可以改写为——
There are many things that one can do
2、There's no（或者 not any）room to put at this at/in (in the car).（room 和 to put this at/in是动宾关系）,可以改写为——
There's no room at/in which we can put this in the car.或 There's no room which we can put this at/in (in the car).
3、I have something to say.（something 和 to say 是动宾关系）,可改写为
——I have something which I will say.
4、He is always the first one to come.（the first one 和to come 是主谓关系）,可改写为
——He was always the first who could come.
5、That’s the way to do it.（way 和to do it 之间是动词和方式状语关系）,可改写为
——That’s the way in which one can do it.
6、There's no room to put this in the car.（room 和to put this 是动词和处所状语关系）,可改写为
——There's no room where we can put this in the car.或者 There's no room at which we can put this in the car.
二、如果这种结构中的名词和不定式没有任何逻辑关系,不定式可能就是整个句子的目的状语.这种情况下,不定式可以用 in order to do 或 so as to do 改写,如：
1、You must come to my office to see me on Sunday.可改写为
——You must come to my office in order to see me on Sunday 或 You must come to my office so as to see me on Sunday.
2、We harried to the school to be in time for the parents meeting.可改写为
——We harried to the school in order to be in time for the parents meeting.
三、there 后是否跟 to do 或 doing 取决于be 后的主语是无行为能力的事物还是有行为能力的人.
1、there is something to do 表示“有某事要做”,to do 是由人实施的,something是行为对象.（例句见上）
2、there is someone doing 表示“有人在做某事”,doing 是由someone 实施的,如：
There are some students playing football on the playground.
因此 there are many things to do 是正确的,there are many thing doing 是错误的.
四、I can't find a quiet place to study 中 place 和to study 是动词何处所状语关系,等于 I can't find a quiet place where I can study,因此应该是定语.
英语是英语,汉语是汉语,英语的语法结构不能翻译为汉语进行解释,事实上,"我找不到安静的学习场所" 和 "我找不到安静的场所来学习.",是汉语中同一个意思的两种表达方法,并不能证明后者就是目的状语,而且用目的状语解释也有些牵强附会,“为了学习我找不到安静的地方”该作何解释呢!倒是可以说“为了学习我不找吵闹的地方”.