Expressing Purpose can be done in different ways, some of them are with: To, In order to, so as to, So that, In order that, For, In case and Lest.
Expressing Purpose with To + Infinitive
- He joined a language center to learn English. (the purpose behind his joining a language center was to learn English)
- She went to the library to study. (the purpose behind her going to the library was to study)
- They stopped to talk to him (the purpose behind their stopping was to talk to him)
Expressing Purpose with In order to + infinitive
- He joined a language center in order to learn English. (the purpose behind his joining a language center was to learn English)
- She went to the library in order to study. (the purpose behind her going to the library was to study)
- They stopped in order to talk to him (the purpose behind their stopping was to talk to him)
- He joined a Gym in order not to get fat.
- She woke up early in order not to be late for school.
Expressing Purpose with So as to + infinitive
- He joined a language center so as to learn English. (the purpose behind his joining a language center was to learn English)
- She went to the library so as to study. (the purpose behind her going to the library was to study)
- They stopped so as to talk to him (the purpose behind their stopping was to talk to him)
- He joined a Gym so as not to get fat.
- She woke up early so as not to be late for school.
Expressing Purpose with So that + subject + modal verbs
- He joined a language center so that he could learn English. (the purpose behind his joining a language center was to learn English)
- She went to the library so that she could study. (the purpose behind her going to the library was to study)
- She goes to the library so that she can study.
- They stopped so that they could talk to him (the purpose behind their stopping was to talk to him)
- He exercises regularly so that he will not get obese
- She woke up early so that she would not be late for school.
Expressing Purpose with In order that + subject + modal verbs
- He joined a language center in order he could learn English. (the purpose behind his joining a language center was to learn English)
- She went to the library in order that she could study. (the purpose behind her going to the library was to study)
- She goes to the library in order that she can study.
- They stopped in order that they could talk to him (the purpose behind their stopping was to talk to him)
- He exercises regularly in order that he will not get obese
- She woke up early in order that she would not be late for school.
Expressing Purpose with For + gerund or nouns
- I exercise for pleasure
- This lesson is for explaining purpose
- A key is a tool for opening doors
Expressing Purpose with In case
In case means in order to be prepared for something that may happen
- I’ll make a sandwich in case you are hungry
- She keeps aspirin in her house in case she feels sick.
Expressing Purpose with Lest
Lest means for fear that or with the intention of preventing. It is usually used in formal written English
- People are afraid of going out lest they get infected by Covid-19 disease
- She was worried lest she had a bad mark in the test
