There are two common ways to express that an action we do has a purpose: the particle to and the conjunction so that.
For example:
I bookmarked the webpage to view it later. (to view it later is the purpose)
I bookmarked the webpage so that I could easily find it later. (to find it later is the purpose)
to / in order to / so as to + infinitive
We say to + infinitive or, more formally, in order to + infinitive, so as to + infinitive when the same subject does the action and pursues the goal.
Examples
We need the key to unlock this door. (We need the key if we want to open this door.)
In order to pass the exam, the students should revise all their notes. (The students should revise them if they want to pass the exam.)
Pay attention! If we need the negative, we say so as not to, less frequently in order not to.
For example:
He set the alarm clock for 5 o'clock so as not to be late for his flight. (WRONG He set the alarm clock for 5 o'clock not to be late for his flight.)
so (that) + subject + verb
"So that", or its shorter informal version "so", connects two parts (clauses) of the sentence. That means we have a subject and a verb following "so that". It is common to put a modal verb after "so that" (for instance, won't/wouldn't or can/could), but not necessarily.
Examples
I'll come home early so that we can have dinner together.
Let's have a snack now so we don't have to stop on our way.
There are two common ways to express that an action we do has a purpose: the particle to and the conjunction so that.
For example:
I bookmarked the webpage to view it later. (to view it later is the purpose)
I bookmarked the webpage so that I could easily find it later. (to find it later is the purpose)
to / in order to / so as to + infinitive
We say to + infinitive or, more formally, in order to + infinitive, so as to + infinitive when the same subject does the action and pursues the goal.
Examples: We need the key to unlock this door. (We need the key if we want to open this door.)
In order to pass the exam, the students should revise all their notes. (The students should revise them if they want to pass the exam.)
Pay attention! If we need the negative, we say so as not to, less frequently in order not to.
For example: He set the alarm clock for 5 o'clock so as not to be late for his flight. (WRONG He set the alarm clock for 5 o'clock not to be late for his flight.)
so (that) + subject + verb
"So that", or its shorter informal version "so", connects two parts (clauses) of the sentence. That means we have a subject and a verb following "so that". It is common to put a modal verb after "so that" (for instance, won't/wouldn't or can/could), but not necessarily.
Examples: I'll come home early so that we can have dinner together.
Let's have a snack now so we don't have to stop on our way.
Put the words in the right order to make up sentences.
1) The police officers were dressed in civikian clothes __________________________________
attention/ so/ as/ to/ not / attract
2)I won’t turn the music on ______________________________
as/ so/ you /to /not/ disturb
3)He sometimes takes sleeping pills ____________________________
get / order/ to sleep / to / in
4)They advanced cautiously _____________________________
not / so/ as / to/ make noise
5)Miranda studied hard __________________________
as / so/ not/ to/ fail the exam/
6)We set off early __________________________
to/ not/ as/ so/ miss the flight/
Put the words in the right order to make up sentences.
1) The police officers were dressed in civikian clothes __________________________________
attention/ so/ as/ to/ not / attract
2)I won’t turn the music on ______________________________
as/ so/ you /to /not/ disturb
3)He sometimes takes sleeping pills ____________________________
get / order/ to sleep / to / in
4)They advanced cautiously _____________________________
not / so/ as / to/ make noise
5)Miranda studied hard __________________________
as / so/ not/ to/ fail the exam/
6)We set off early __________________________
to/ not/ as/ so/ miss the flight/
Put the words in the right order to make up sentences.
1) The police officers were dressed in civikian clothes __________________________________
attention/ so/ as/ to/ not / attract
2)I won’t turn the music on ______________________________
as/ so/ you /to /not/ disturb
3)He sometimes takes sleeping pills ____________________________
get / order/ to sleep / to / in
4)They advanced cautiously _____________________________
not / so/ as / to/ make noise
5)Miranda studied hard __________________________
as / so/ not/ to/ fail the exam/
6)We set off early __________________________
to/ not/ as/ so/ miss the flight/
Put the words in the right order to make up sentences.
1) The police officers were dressed in civikian clothes __________________________________
attention/ so/ as/ to/ not / attract
2)I won’t turn the music on ______________________________
as/ so/ you /to /not/ disturb
3)He sometimes takes sleeping pills ____________________________
get / order/ to sleep / to / in
4)They advanced cautiously _____________________________
not / so/ as / to/ make noise
5)Miranda studied hard __________________________
as / so/ not/ to/ fail the exam/
6)We set off early __________________________
to/ not/ as/ so/ miss the flight/
Choose so that or in order to to complete the sentences.
窗体顶端
1. I have started an English course 
improve my English.
2. I'm studying very hard nowadays I can pass my class.
3. I went to bed early wake up early.
4. We all put on our jackets keep warm.
5. One should exercise regularly keep their body in shape.
6. Make sure your bags are tagged you can find them easily.
7. I had to take a cab I wouldn't be late for my appointment.
8. I took my digital camera with me I could take some photos during my trip.
9. I need to take out a loan from a finance company buy a new car.
10. Jason turned off the radio he could concentrate on his work.
窗体底端
Choose so that or in order to to complete the sentences.
窗体顶端
1. I have started an English course improve my English.
2. I'm studying very hard nowadays I can pass my class.
3. I went to bed early wake up early.
4. We all put on our jackets keep warm.
5. One should exercise regularly keep their body in shape.
6. Make sure your bags are tagged you can find them easily.
7. I had to take a cab I wouldn't be late for my appointment.
8. I took my digital camera with me I could take some photos during my trip.
9. I need to take out a loan from a finance company buy a new car.
10. Jason turned off the radio he could concentrate on his work.
窗体底端
Choose so that or in order to to complete the sentences.
窗体顶端
1. I have started an English course improve my English.
2. I'm studying very hard nowadays I can pass my class.
3. I went to bed early wake up early.
4. We all put on our jackets keep warm.
5. One should exercise regularly keep their body in shape.
6. Make sure your bags are tagged you can find them easily.
7. I had to take a cab I wouldn't be late for my appointment.
8. I took my digital camera with me I could take some photos during my trip.
9. I need to take out a loan from a finance company buy a new car.
10. Jason turned off the radio he could concentrate on his work.
窗体底端
