Clauses of reason, result and purpose
B1 IntermediateClauses of reason, result, and purpose explain why something happens, the effect of an action, or the intention behind it. These structures use specific conjunctions and infinitives to connect ideas logically.
Overview
These clauses provide essential context for actions. Reason explains the cause using because or since. Result describes the consequence using so. Purpose explains the goal using to, in order to, or so that.
Form
Main Clause + Conjunction + Subordinate Clause / Infinitive
Reason and result clauses typically connect two full clauses. Purpose clauses can use an infinitive or a full clause depending on the conjunction.
Reason vs. Purpose vs. Result
Note that so expresses a result, while so that expresses a purpose and is usually followed by a modal verb like can or could.
| Function | Common Conjunctions | Example |
|---|---|---|
| Reason (Why?) | because, as, since | I stayed home because it was raining. |
| Result (What happened?) | so | It was raining, so I stayed home. |
| Purpose (What is the goal?) | to, in order to, so that | I stayed home to avoid the rain. |
Examples
Common mistakes
I went to the shop for buying milk.
I went to the shop to buy milk.
Use the 'to-infinitive' to express purpose, not 'for' + -ing.
It was late, because I took a taxi.
It was late, so I took a taxi.
Do not confuse the cause with the result. The taxi was the result of it being late.
Practice
Complete the sentence: We took a map ___ we wouldn't get lost.
Show answer
so that
Answer:so that
Why:'So that' is used here to express the purpose of taking the map, followed by a clause with a modal verb.
Choose the correct word: ___ it was a public holiday, all the banks were closed.
Show answer
Because / Since / As
Answer:Because / Since / As
Why:A conjunction of reason is needed to explain why the banks were closed.
Rewrite using 'in order to': She joined the gym because she wanted to get fit.
Show answer
She joined the gym in order to get fit.
Answer:She joined the gym in order to get fit.
Why:'In order to' replaces the reason clause to express the same idea as a purpose.