Conditionals

Conditional Conjunctions & Phrases

Beyond if

Conditions don't always begin with if. A small set of conjunctions and phrases introduces a condition too, and each one adds a slightly different meaning — a requirement, a precaution, a moment in time, or a reason.

Conjunction	Meaning	Example
as long as	only if	You can borrow it as long as* you return it.*
provided that	only if	We'll fund the study provided that* you publish the data.*
unless	except if	We'll be late unless* we hurry.*
in case	because it is possible that	Take a map in case* you get lost.*
once	at the moment something happens	Call me once* you arrive.*
since	because it is true that	Since you're here, let's start.

The shared rule: like if, none of these conjunctions takes will or would in its own clause, even when the meaning is future: Once you arrive, send me a message.

Requirement · unless, as long as, provided that

Unless means except if. The negative idea is already inside the word, so the clause after it stays positive.

unless + positive clause = if ... not

You'll miss the train unless you hurry. = if you don't hurry

Unless the results are clear, we repeat the test.

As long as and provided that both mean only if: they state the one condition that must be met. Provided that (also providing) is the more formal of the two and is common in contracts and rules; as long as is the everyday choice.

You can use the lab as long as you book it first.

The grant continues provided that the team submits a yearly report.

In case is not if

This is the difference students get wrong most often. In case describes a precaution: you act first, because something might happen later. If describes a reaction: you act only when the condition is true.

I'll take an umbrella in case it rains. → I take it now; maybe it never rains.

I'll take an umbrella if it rains. → I only take it when the rain starts.

Tip: if you can add just to be safe to the sentence, you need in case.

Once and since

Once means at the moment something happens — very close to as soon as. It presents the event as certain, not as a possibility, and it takes a present tense for future time.

Once the funding arrives, we start the second phase.

You'll understand the graph once you read the notes.

Since here does not mark time. It means because it is true that, and it introduces a reason the listener already accepts.

Since nobody objected, the proposal was approved.

We can finish early since the equipment is already set up.

⚠ Common mistakes:
✗ Unless you don't hurry, you'll be late. → ✓ Unless you hurry, you'll be late.
✗ Once you will arrive, call me. → ✓ Once you arrive, call me.
✗ Provided that you will pay, we'll deliver. → ✓ Provided that you pay, we'll deliver.
✗ Take a coat in case it will be cold. → ✓ in case it is cold
✗ I'll phone you in case I arrive. → ✓ I'll phone you when I arrive. (arriving is certain)

Match the Conjunction to its Meaning

Click a conjunction on the left, then click the meaning that matches it on the right.

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Fill in the Gaps

Complete each sentence with the right conjunction. The meaning is given in brackets.

Find the Mistake

One sentence, four underlined parts. Click the lettered part that contains the error — it is not always in the grammar of this lesson, so read the whole sentence.

Put the Words in Order

Click the words to build the correct sentence. Click a placed word to remove it.

Answer the Questions

Write your own answers using the conjunction given. Then click "Show Model Answer" to compare.