Goodnight or Good Night? Grammatical Correctness Matters

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It’s been a long day, and you’re ready to hit the hay. You say goodnight to your partner and head off to bed. But wait – did you say good night or goodnight?

Believe it or not, there is a grammatical difference between the two! In this blog post, we will discuss the correct usage of good night and goodnight and why it matters.

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What Is the Difference Between Goodnight and Good Night?

When we are ready to go to bed, we say, “Good night!” Good night is an interjection. An interjection is a word that shows feeling or emotion. In this case, “good night” is used to wish someone good luck in their sleep.

However, if we want to use an adjective or noun, we would use “goodnight” as one word. For example, in “a goodnight kiss,” the word “goodnight” acts as an adjective. “His goodnights were soothing and sweet” is an example sentence in which “goodnight” is used as a noun.

Similar examples include “every day” (noun) and “everyday” (adjective).

In British English, “goodnight” can also be used as a one-word spelling as an interjection. See the Oxford UK Dictionary for examples.

Good Night Meaning

Good night is a phrase used as an exclamation to wish someone good luck in their sleep.

Good night is not used as a greeting. It is a farewell phrase used to say goodbye before going to bed.

“Goodnight,” as one word, can also be used as an injection, according to the Oxford UK Dictionary. In our examples, however, we are just going to stick with “good night” as the spelling of the interjection.

Example Sentences with Good Night

  • “Good night, Lucy!”
  • “Good night, Joe, see you in the morning!”
  • “Have a good night!”
  • “Good night, Christian, sweet dreams!”

Why Do We Say Good Night?

In the morning, we say “good morning.” This phrase is used to wish someone well in the morning.

In the afternoon, we say “good afternoon.” This phrase is used to wish someone well in the afternoon.

In the evening, we say “good evening.” Why? This phrase is used to wish someone well in the evening.

We can also say “good day.” This phrase is used to wish someone good luck in the day.

And, at night, we say “good night.” Why? You know it! This phrase is used to wish someone good luck in their sleep.

If we say, “Have a good night” it means that the person is out socializing, and we wish them a good time. (good is used as an adjective here to describe the night)

“I hope you have a good night at work” could be wished to someone who has nightly shifts.

See our article for responding to well wishes-> Best Ways To Respond To “Hope All is Well”

Goodnight Meaning

As an adjective, “goodnight” means “of or relating to the night.”

Example Sentences with Goodnight (Adjective)

  • The woman gave her children a goodnight kiss.
  • Sue sang some goodnight songs and rhymes.
  • The children gave a goodnight hug to their dog.
  • Mike said a goodnight prayer before sleeping.
  • Lily sent a goodnight text to her crush.

In each of these sentences, “goodnight” is being used as an adjective to modify the nouns and describe them in more detail.

Example Sentences with Goodnight (Noun)

  • They said their goodnights to their parents before going to bed.
  • Tom bade Mary farewell with his usual goodnight.
  • His goodnights were sweet and soothing.

In each of these sentences, goodnight is being used as a noun.

To say your goodnights is to wish everyone a good night before bed.

Is Good-night Correct?

While not featured in most dictionaries, the Collins US Dictionary offers “good-night” as a noun. This might be an alternate spelling, but it doesn’t seem to be widely in use and many websites are stating that it is incorrect to hyphenate it.

While I haven’t seen this spelling of the word before, it might be a good idea to check your style guide if you are still unsure.

For example, he said his good-nights to his friends at 9 pm.

Goodbye vs Good Night

Good night are two seperate words, similar to “good morning” and “good day.” We can also spell “goodnight” as one word, as discussed.

Goodbye is one word. Bye is shortened form of goodbye; therefore, we cannot treat it as two separate words.

Why Grammatical Correctness Matters

Correct grammar usage is important, especially in the written text where the mistakes become more apparent. While “good night” and “goodnight” are pronounced in the same way, they are spelled differently depending on the context.

Let’s examine the differences between the following sentences:

I gave my son a goodnight kiss.

I gave my son a good night kiss.

Which sentence is correct?

The first sentence means that I gave my son a kiss at night. “Goodnight” is used as an adjective and lets us know more about the kiss and the emotion behind it.

In the second sentence, the “good” is separated from the “night.” This means that we could be saying that “good” is the adjective. Could we really describe a night kiss to our son as “good” or “bad?”

Sentence two is a misplaced modifier. This means that it provides an unintended meaning due to its misplacement in the sentence.

Therefore, the first sentence’s spelling is correct– “I gave my son a goodnight kiss.”


Alternatives to Good Night

There are other phrases that can be used to wish someone good luck before bed.

  • “I hope you have a good sleep.”
  • “Night.”
  • “Sweet dreams.”

For more alternatives, see our article: Ways to Say Good Night.

Origin of The Phrase “Good Night”

“Good night” was an exclamation of surprise used since 1893. It comes from “good” (adjective) and night (noun). “Good” meant “fortunate, prosperous, favorable” in late Old English.

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Is Good Night a Greeting?

No, “good night” is not a greeting. It is used to wish someone good luck before they go to bed.

How Do You Respond To Good Night?

When someone says good night, you can simply reply with “night” or “sweet dreams” to wish them good night as well.

Do We Say Goodnight or Good Night?

Both are correct. Good night is a farewell interjection, whereas goodnight is a noun or adjective. 

In Conclusion

When it comes to good night, the correct usage depends on whether you are using it as an interjection, a noun or an adjective.

As a farewell interjection, good night should usually be spelled as two words. As a noun or adjective, goodnight can be spelled as one word.

I hope you enjoyed this article. If you did, why not share it with your friends and tell me what spelling you use in the comments section below!

Caitriona Maria is an education writer and founder of TPR Teaching, crafting inspiring pieces that promote the importance of developing new skills. For 7 years, she has been committed to providing students with the best learning opportunities possible, both domestically and abroad. Dedicated to unlocking students' potential, Caitriona has taught English in several countries and continues to explore new cultures through her travels.

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