When to hyphenate… and when not to
I’m not going to cover every instance of hyphenation, just one specific kind: compound adjectives.
I work with a lot of professional writers and when editing their work, I’m surprised at how many get this rule wrong or apply it randomly.
Sometimes I do, too. I am not the perfect writer! Far from it. But I’ve come up with a neat trick to help me figure it out. And that’s what being a smarter writer is all about. You don’t need to be a grammar nerd. Nope. Instead, a smart writer stockpiles a bunch of tips that help them improve their writing.
Some grammar specialists would probably tear this explanation to shreds. But it works for me and I’m hoping it will work for you, too.

What is a compound adjective?
Let’s look at what compound adjectives are.
‘Compound’ means to bring two or more things together.
Compound adjectives are exactly this – bringing 2 or more words together to create an adjective.
And when you do, those words must be hyphenated.
When do you hyphenate?
Let’s use the phrase ‘easy to bake’ as our first example.
If you use this phrase as an adjective, add hyphens. If it’s not an adjective, don’t hyphenate it.
While that sounds simple in theory, how does it roll out in practice?
- I love easy-to-bake cupcakes.
In this example, the phrase ‘easy-to-bake’ is an adjective. It’s describing cupcakes. The phrase becomes hyphenated to ‘compound’ to the 2 or more words into a single adjective.
Usually, if the phrase comes before the noun (‘cupcakes’ in this example), it’s an adjective. That’s one trick to help remember if the word is hyphenated.
- Cupcakes are easy to bake.
In this instance, ‘easy to bake’ is not a compound adjective. It’s an adjective (easy) plus a verb (to bake), so we don’t hyphenate it.
Here are some more examples:
- ✅ My broken-down car needs to be towed.
- ✅ My car has broken down and needs to be towed.
- ✅ The timetable has an up-to-date schedule.
- ✅ The schedule in the timetable is up to date.
- ✅ Hard-to-kill zombies are dangerous.
- ✅ Zombies that are hard to kill are dangerous.
Green zombies and hyphenation

Here’s my second trick. Choose your favourite colour. Mine’s green. Well, today, anyway.
Let’s look at the zombie examples from the above list.
See if you can swap the adjectives in the zombie examples for the colour you just chose and if it still makes sense, at least from a grammar perspective.
Hard-to-kill zombies are dangerous.
Let’s swap the compound adjective ‘hard-to-kill’ with ‘green’
✅ Green zombies are dangerous.
The sentence still works. That’s how I know ‘hard-to-kill’ should be hyphenated.
Zombies that are hard to kill are dangerous.
Let’s swap the adjective ‘hard’ for ‘green’ and see what happens.
❌ Zombies that are green to kill are dangerous.
It doesn’t work, so in this instance, ‘hard to kill’ doesn’t need to be hyphenated.
Let’s do the cupcake one.
I love easy-to-bake cupcakes.
✅ I love green cupcakes.
Cupcakes are easy to bake.
❌ Cupcakes are green to make.
If you can swap the adjective out for ‘green’ and it still makes sense then the 2 or more words you used to describe the noun must be hyphenated.
Learning tricks like this is helping me to become a better writer.
Next time you’re wondering if you should hyphenate, think of the green zombies!
When not to hyphenate
When you use adverbs (those words that describe verbs and that usually end in ‘ly’) you generally don’t need to hyphenate.
For example, you don’t need to hyphenate these phrases because they include adverbs:
- a highly regarded soccer player
- a closely watched person of interest
- a slowly boiling pot
- a deliciously fattening cupcake
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