Is Heartbeat One Word or Two?


Updated on August 22, 2019 | This or That?


What’s the Difference between Heartbeat and Heart Beat?

The decision of whether to use heartbeat or heart beat can be easy, or it can be like splitting hairs.

The one-word version (heartbeat) is a single noun which refers to a pulsation of the heart. This would be used in a sentence like the following.

Your heartbeat is a little fast.

Meanwhile, the two-word version (heart beat) is literally the noun heart followed by the verb beat. The two-word version would be used in a sentence like the example below.

My heart beat a thousand miles a minute when that scary clown jumped out at me.


How to Decide Whether to Use Heartbeat or Heart Beat

When followed immediately by a verb, heartbeat should be one word.

Notice how the word heartbeat in the first example above needed to be followed by a verb (is) to make a complete sentence, whereas the phrase heart beat in the second example did not. This is because beat is the sentence’s verb. The presence of a verb immediately following heartbeat/heart beat indicates that the one-word version should be used. Here are some more examples to illustrate this (the verbs are enclosed in brackets):

Correct: His heartbeat [was] rhythmic and soothing.

Correct: His heartbeat [made] me sleepy.

Incorrect: His heart beat [was] rhythmic and soothing.

Incorrect: His heart beat [made] me sleepy.


When immediately followed by an adverb, heart beat should usually be two words.

(If you need to brush up on what an adverb is, feel free to give my article on adverbs a read.)

The presence of an adverb can also determine which form of heartbeat/heart beat should be used. If the term is described by an adverb (e.g., quickly, irregularly, soothingly) the two-word version should usually be used. This because it is impossible for an adverb to describe a noun. The examples below illustrate this rule in action.

Correct: His heart beat [rapidly].

Incorrect: His heartbeat [rapidly].


However, in some cases, the one-word version can be followed by an adverb. This is acceptable only when that adverb is followed by a verb. In such a case, the adverb isn’t referring to the noun heartbeat but instead to the following verb,. which is perfectly acceptable.

Incorrect: His heartbeat rapidly.

Correct: His heartbeat rapidly increased.


What if heartbeat/heart beat is at the end of a sentence?

Unfortunately, sentences do not always include the clues discussed above. In some instances, particularly when heart beat/heartbeat is at the end of a sentence, both the one-word and the two-word version can be acceptable. The difference in the sentence’s meaning would be very slight. For example, compare the two sentences below:

Correct: He listened to her heart beat.

Also correct: He listened to her heartbeat.

The meanings of these two sentences are virtually identical. The first means that he listed to her heart as it performed the act of beating; the second means that he listened to the palpitations of her heart. In this example, if you wanted the focus to be on the girl’s heart, you should use heart beat; if you wanted the focus to be on the sound of the heart, you should use heartbeat.


heartbeat. (n.d.). Unabridged. Retrieved January 4, 2018 from