介词

We commonly use prepositions to show a relationship in space or time or a logical relationship between two or more people, places or things. Prepositions are most commonly followed by a noun phrase or pronoun

within

space

Within means ‘inside or not further than a particular area or space’:

For example.

• People who live within the city pay higher local taxes than people who live just outside the city.

time

We can use within to refer to time.

• I’ve noticed her change within a very short time.

within and in

in和within用于一段时间的结束, within更正式.

• The should get the job finished within a few days.

within更强调不超过特定的区域、空间、时间.

with

当讨论的是动作时，使用by而不用with

• He got into the house by breaking the windows

当连接的是object或instrument，使用with而不用by

• He broke the window with a rock.

as

We use as with a noun to refer to the role or purpose of a person or thing.

• I worked as a waiter when I was a student.