This guest post is by Alice Sudlow. Alice is a reader, writer, freelance editor, and self-proclaimed grammar nazi. When she’s not picking apart grammatical errors on product packaging and in news articles, you’ll find her curled up with a YA novel and a cup of tea. You can follow her on LinkedIn.

Of all the nuances of grammar in the English language, this is my greatest pet peeve. No, it’s not “its vs. it’s.” It’s not “there, their, and they’re.” It’s not even the Oxford comma.

Let’s talk conditional sentences.

ollow These Rules To Write Conditional Sentences Correctly

What Is a Conditional Sentence?

A conditional sentence is a sentence that describes a hypothetical situation, like an action or event, and the result of that situation.

Confused? Here’s an easy way to think about it: a conditional sentence can usually use the words “if” and “then.” Here’s an example:

If a zombie apocalypse occurs, then I want to survive.

Real vs. Unreal Conditional Sentences

There are two major types of conditional sentences, and you use them based on how likely the hypothetical situation is to occur.

Real conditional sentences deal with factors that are certain.

If I go to the hardware store today, then I will get a crowbar.

It’s very possible that I’ll actually go to the hardware store today, and when I'm there, I will definitely get a crowbar. So this is a real conditional sentence.

On the other hand, unreal conditional sentences deal with imaginary situations, things that aren’t likely to happen.

If their chainsaws were not so expensive, then I would get one of those, too.

The problem is that chainsaws are expensive, so I definitely won’t get one. Since finding a low-priced chainsaw at that hardware store is an imaginary situation, this conditional sentence is unreal.

Formulas for Writing Conditional Sentences

Conditional Sentences Meet Zombies

Writing a conditional sentence is like following a formula. Try these common ones out for size:

The Present Real Conditional: If [present situation], then [present result]

If I buy hefty tools, I put them in my zombie preparedness kit.

Note: you can often omit the “then” from conditional sentences. Most of the examples in this post work with or without the “then.” Most writers will omit the “then” in almost all their conditional sentences for simplicity sake.

The Present Unreal Conditional: If [simple past situation], then [conditional result].

If I bought a chainsaw, then I would put it in my zombie preparedness kit, too.

The Past Real Conditional: If [simple past situation], then [simple past result].

Before I created my zombie preparedness kit, I avoided watching zombie movies because if I watched them, then I got really scared.

The Future Real Conditional: If [present], then [future].

If one day we face a zombie apocalypse, I will be ready.

Reversing “If and Then” Order

All formulas for conditional sentences hold true if you reverse the if/then clauses:

I would buy a chainsaw if I could afford it.

Or even if you remove the words “if” and “then” altogether:

Had I a chainsaw, I would feel more prepared.

You Can Use “When” in Conditional Sentences, Too

Using “when” instead of “if” will change the meaning of these sentences, but they’re still conditional sentences either way. For example:

When I buy hefty tools, I put them in my zombie preparedness kit.

When Things Go Wrong With Conditional Sentences

Have you ever heard someone say, “If I would have”?

If I would have known the chainsaws were on sale last week, then I would have purchased one.

This is so wrong.

I hear it all the time, but there’s a major problem here. Remember all those formulas we talked about? Here’s the one we need now:

The Past Unreal Conditional: “If [past perfect situation], then [conditional past result].”

Or to put it more simply, “If I had [past participle], then I would have [past participle].”

“Would have purchased” is the conditional past tense of the verb “to purchase.” It fits perfectly after “then.” But “would have known” is the conditional past, too, so it doesn’t fit. The past perfect of “to know” is “had known.”
So the correct sentence is:

If I had known the chainsaws were on sale last week, then I would have purchased one.

Bonus! More Misused Conditional Sentences

Here’s one more instance where people commonly (but mistakenly) use the conditional past tense:

I wish I would have known about the sale at the hardware store!


Like the if-clauses above, “I wish” must be followed by the past perfect. So if you realize you missed out on a great opportunity to beef up your zombie preparedness kit and you regret not snagging a deal on that chainsaw last week, you would say,

I wish I had known about the sale at the hardware store!

This is the correct version.

And with that, you know all you need to if you never want to misuse conditional sentences again! If I were standing next to you, then I'd give you a high five! (See what I did there?)

 How about you? Do you enjoy using conditional sentences in writing? Let us know in the comments section.


Write a scene about a regretful character. Maybe she did something she shouldn’t have done. Maybe he didn’t do something he should have done. If something had happened, then what would have happened? What does this person wish they’d done differently?

Write about your character’s if/then or “I wish” mistake for fifteen minutes, then post your practice in the comments. And if you post, remember to give feedback to your fellow writers.

Bonus: Today, find a real-life if/then or “I wish” mistake. Listen to the conversations around you, pay attention to the lyrics of songs on the radio, and double-check the newspaper, books on your shelf, and cereal boxes. When you find an instance where the conditional past is misused, share it in the comments.

Alice Sudlow is the Editor-in-Chief of The Write Practice and a Story Grid certified developmental editor. Her specialty is in crafting transformative character arcs in young adult novels. She also has a keen eye for comma splices, misplaced hyphens, and well-turned sentences, and is known for her eagle-eyed copywriter skills. Get her free guide to how to edit your novel at

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