If-clauses
If-clauses are used to express that the action of the main clause. There are three types of if-clauses. In this lesson, we will discuss them.
What Are Condition Clauses?
Each conditional sentence consists of two clauses, one clause expresses the condition that must be met (the condition clause) and the other, main clause, expresses the result in case the condition is met. The conditional clause is marked by a condition marker while the main clause is unmarked.
Condition Markers
Condition markers are the words or phrases used to introduce condition clauses. The following is a list of condition markers with the type of condition they express:
Here are some examples:
Conditional type I with "Unless"
Conditional type I with "Provided that"
I’ll call you
Conditional type I with "In case"
Conditional type I using inversion with "should"
Conditional type II with "Suppose"
Conditional type II using inversion with "were"
Conditional type III with "If"
Conditional type III using inversion with "had"
Unless
As you can see in these examples, "unless" functions differently from the other condition markers. It is used to express a condition under which the main clause will not occur. In other words, it specifies a negative condition.
You won’t succeed
This sentence means "if you don't work hard, you won't success".
Condition Markers vs. Subordinating Conjunctions
Subordinating conjunctions can be used in zero conditional sentences to form statements about general facts or habits. "If" and "unless" also act as subordinating conjunctions in zero conditionals. However, subordinating conjunctions such as "when", "whenever", and "while" cannot be used in the other types of conditional clauses. For example:
The result always happens whenever the action occurs.
Plants don’t grow
Condition Clause: Placement
Since the condition clause is marked, it can appear at the beginning, middle, or end of the sentence. However, the punctuation of the sentence differs for each position:
- If the condition clause comes at the beginning of the sentence, a comma is used after it.
- It the condition clause comes at the end of the sentence, no comma is needed.
- If the condition clause comes in the middle of the sentence, two commas are used on either side of it.
Here are some examples:
the condition clause at the beginning
I will be able to afford the rent
the condition clause at the end
Tell him,
the condition clause in the middle
Condition Clause: Types
The tense of the verb in the condition clause differs depending on the type of the condition expressed in the sentence. While zero conditionals express general truths, first conditionals talk about realistic possibilities, second conditionals refer to hypothetical situations in present or future, and third conditionals express hypothetical or unreal situations in the past. The tense of the verbs in the condition clause and the main clause for each of these types is as follows:
- Zero conditional: [Present simple] + [Present simple]
When you
- First Conditional: [Present simple] + [Future simple/Modals + Base verb]
If she
- Second Conditional: [Past simple] + [Would + Base verb]
If I
- Third Conditional: [Past perfect] + [Modal + Present perfect]
If I