Purpose and Reason ClausesYou use a purpose clause when you aresaying what someone’s intention is when theydo something. The most common type ofpurpose clause is a ‘to’-infinitive clause.The children sleep together to keep warm.They locked the door to stop us from gettingin.
Purpose and Reason ClausesInstead of using an ordinary ‘to’-infinitive, youoften use ‘in order’ or ‘so as to’ with aninfinitive.He was giving up his job in order to stay athome.I keep the window open, so as to let fresh airin.
Purpose and Reason ClausesTo make a purpose clause negative, you haveto use ‘in order not to’ or ‘so as not to’ with aninfinitive.I would have to give myself something to doin order not to be bored.They went on foot, so as not to be heard.
Purpose and Reason ClausesAnother way of making purpose clausesnegative is by using ‘to avoid’ with an ‘-ing’form or a noun group.I had to turn away to avoid letting him see mysmile.They drove through town to avoid themotorway.
Purpose and Reason ClausesAnother type of purpose clause begins with ‘inorder that’, ‘so’, or ‘so that’. These clausesusually contain a modal.When the main clause refers to the present,you usually use ‘can’, ‘may’, or ‘shall’ in thepurpose clause.
Purpose and Reason ClausesAny hole should be fenced so that peoplecan’t fall down them.I have drawn a diagram so that myexplanation will be clearer.
Purpose and Reason ClausesWhen the main clause refers to the past youusually use ‘could’, ‘might’, ‘should’, or ‘would’in the purpose clause.She said she wanted tea ready at six so shecould be out by eight,Someone lifted Philip onto his shoulder sothat he might see the procession.
Purpose and Reason ClausesYou use ‘in order that’, ‘so’, and ‘so that’,when the subject of the purpose clause isdifferent from the subject of the main clause.For example, you say ‘I’ve underlined it sothat it will be easier.’ You do not say ‘I underunderlined it to be easier’.
Purpose and Reason ClausesYou can also talk about the purpose of anaction by using a prepositional phraseintroduced by ‘for’.She went out for a run.They said they did it for fun.I usually check, just for safety’s sake.
Purpose and Reason ClausesYou use a reason clause when you want toexplain why someone does something or whyit happens. When you are simply giving thereason for something, you use ‘because’,‘since’, or ‘as’.
Purpose and Reason ClausesI couldn’t see Helen’s expression, becauseher head was turned.Since it was Saturday, he stayed in bed.As he had been up since 4 am, he was verytired.
Purpose and Reason ClausesYou can also use ‘why’ and a reportedquestion to talk about the reason for anaction.I asked him why he had come.
Purpose and Reason ClausesWhen you are talking about a possiblesituation which explains the reason whysomeone does something, you use ‘in case’or ‘just in case’.
Purpose and Reason ClausesI’ve got the keys in case we want to go inside.I’m here just in case something unusualhappens.WARNING: You do not use a future tenseafter ‘in case’. You do not say ‘I’ll stay behindin case she’ll arrive later’.