It is normally expressed by the infinitive:
1. The infinitive alone:
– He went to France to learn French.
Where there is a personal object of the main verb, the infinitive may refer to this and not to the subject.
– He sent Tom to the shop to buy bread.
2. In order or so as + infinitive:
In order + infinitive can imply either that the subject wants to perform the action or that he wants it to happen.
So as + infinitive implies only that the subject wants the action to happen.
They are used:
A. With a negative infinitive to express a negative purpose
ü He left his gun outside in order/so as to be at home when he arrived.
B. With to be and to have
ü She left work early in order/so as to be at home when he arrived.
ü She gave up work in order/so as to have more time with her children.
C. When the purpose is less immediate
ü He is studying mathematics in order/so as to qualify for a better job.
D. In longer sentences, to emphasize that the infinitive indicates purpose
ü He took much more trouble over the figures then he usually did in order/so as to show his new boss what a careful worker he was.
E. When the infinitive of purpose
ü In order/so as to show his new boss what a careful worker he was, he took extra trouble over the figures.
F. When there is a personal object but we want the infinitive to refer unambiguously to the subject
ü He sent his son to a boarding school in order/so as to have some peace.
3. In order (but not so as) used to emphasize that the subject really had this purpose in mind
ü He bought diamonds when he was in Amsterdam! That wasn´ t surprising. He went to Amsterdam in order to buy diamonds (not for any other purpose).
4. Infinitive + noun + preposition:
ü I need a corkscrew to open this bottle with.
Here we are talking about a particular purpose. For a general purpose we use for + gerund.
ü A corkscrew is a tool for opening bottles.
Infinitives of purpose after go and come:
It is not normal to use an infinitive of purpose after the imperative or infinitive of go and come. Instead of an imperative + an infinitive of purpose we use 2 imperatives joined by and.
Instead of “Go to find Bill” we say “Go and find Bill” and instead of “Come to talk to Ann” we say “Come and talk to Ann”.
But when go and come are used as gerunds or in any present or past tense, they take the ordinary infinitive of purpose.
ü I´m thinking of going to look for mushrooms.
Clauses of purpose:
Clauses are necessary when the person to whom the purpose refers is different from the subject of the main clause or when the original subject is stated again.
ü Ships carry lifeboats so that the crew can escape if the ship sinks.
ü This knife has a cork handle so that it will float if it falls overboard.
Purpose clauses are usually expressed by so that + will/would or can/could + infinitive. Can/could is used here to mean will/ would be able to.
ü They make 10 p. notes a different size from 5 p. notes so that blind people can tell the difference between them.
ü They wrote the notices in several languages so that foreign tourists could understand them.
Can and will are used when the main verb is in a present, present perfect or future tense. Could and would are used when the main verb is in a past tense.
Purpose clauses can also be formed by so that / in order that / that + may/might or shall/should but they are more formal constructions.
So that can be followed by will/can/may/shall or their past forms while in order that or that are limited to may/shall or their past forms.
That used alone is rarely found except in very dramatic speech or writing or in poetry
Negative purpose clauses:
They are made by putting the auxiliary verb into the negative.
ü He wrote his diary in code so that his wife wouldn´ t be able to read it.
Negative purpose clauses can however be replaced by to prevent + noun/pronoun + gerund or to avoid + gerund.
ü He dyed his beard so that we shouldn´t recognize him/ to prevent us from recognizing him/ to avoid being recognized.
These infinitive phrases are preferred to negative purpose clauses.
In case and lest:
In case + subject + verb can follow a statement or command
ü I don´t let him climb trees in case he tears his trousers
The first action is usually a preparation for or a precaution against the action in the in case clause which is a possible future action.
In case + present tense has the meaning because this may happen, because perhaps this will happen or for fear that this may happen.
In case + past tense has the meaning because this might happen, because perhaps this would happen or for fear that this would happen.
Both present tense and past tense can be replaced by should + infinitive and it would express greater improbability.
Tenses with in case:
Future present tense
Present + in case+ should + infinitive
Conditional past tense
Past + in case+ should + infinitive
ü I always keep candles in the house in case there is a power cut.
ü I always kept candles in the house in case there was a power cut.
Lest means for fear that and is followed by should
ü He doesn´t /didn´t dare to leave the house lest someone should recognize him.
Lest is rarely found except in formal written English.
They convey a direct relationship with the matrix clause. The relationship may be that of cause and effect.
ü He is thin because he hasn´t eaten enough. (the reason of being thin is that he hasn´t eaten enough)
Reason clauses are most commonly introduced by because and since. Other subordinators are as, for (somewhat formal) and seeing (that); because of, owing to, due to + noun.
ü I lent him the money because he needed it.
ü As Jane was the eldest, she looked after the others.
ü Since we live near the sea, we often go sailing.
ü Much has been written about psychic phenomena, for they pose fascinating problems that have yet to be solved
ü Seeing that it is about to rain, we had better leave now.
ü Many of the deaths of older people are due to heart attacks.
ü We were unable to go by train because of the rail strike.
A for-clause must be in final position.
When as is a circumstancial subordinator, the predication may optionally be fronted.
ü Tired as they were, they didn´ t stay up for the late news.
In view of the fact that can be expressed by as, since and seeing that but not because
ü As/Since/ Seeing that Tom knows French, he´ d better do the talking.
Where as, since and seeing that refers to a statement previously made or understood it is replaceable by if.
ü As/Since/ Seeing that (if) you don´ t like Bill why did you invite him?
They are introduced by the subordinators so that and so.
ü We paid him immediately, so (that) he left contented.
Therefore, Consequently, As a result can also be used, but is normal only in fairly formal sentences.
ü We have invested too much money in this project. Consequently, we are in financial difficulties.
ü The Finnish delegate has not yet arrived. Therefore we are postponing the meeting.
ü His wife left him and as a result he became very depressed.
Clauses of result with such/so…… that:
Such is an adjective and is used before an adjective+noun
ü They had such a fierce dog that no one dared go near their house.
So is an adverb and is used before adverbs and with adjectives which are not followed by their nouns.
ü Their dog was so fierce that no one dared go near their house.
But such is never used before much and many, so so is used when much and many are followed by nouns.
ü So many people complained that they took the programme off.
Such + a + adjective + noun is replaceable by so+ adjective + a + noun f.i: such a good man by so good a man. This is only possible when a noun is preceded by a/an.
Sometimes for emphasis so is placed at the beginning of the sentence and then it is followed by the inverted form of the verb.
ü So terrible was the storm that whole roofs were ripped off.
The subordinator that may be omitted from the that-clause. An informal variant substitutes the intensifier that for so and omits the subordinator that.
ü I was that tired I couldn´ t keep my eyes open.
The formal construction so/such ……..as with the infinitive is sometimes used in place of so/such with a that-clause
ü He was such a violent person as to make even his closest companions fear him.
ü His temper was so violent as to make even his closest companions fear him.