A <em>hart</em> is a mature male deer, especially a red deer stag — a rare, literary word you will mostly meet in old poetry, pub names and surnames. <em>Heart</em> is the organ and, by extension, the seat of feeling: "my heart was racing", "she took it to heart". They sound identical, but unless deer are genuinely involved, the word you want is heart.
The core difference
This pair is lopsided. Heart is one of the most common nouns in English; hart is close to obsolete in everyday use. That imbalance is exactly what makes the confusion dangerous — hart is a real dictionary word, so nothing flags it when it lands in the wrong sentence.
How to use heart
Heart covers the organ, the emotions, and the centre of a thing:
- "He was taken to hospital with heart trouble."
- "She didn't have the heart to tell him."
- "That's the heart of the problem."
- "The flat is right in the heart of the city."
The idiom list is enormous: learn by heart, take heart, lose heart, a change of heart, heart of gold, set your heart on, heart-to-heart, wear your heart on your sleeve.
How to use hart
A hart is a male deer, traditionally a red deer stag past a certain age. Its female counterpart is a hind. The word survives in three places:
- Older literature and biblical language, where you may meet a hart panting after water brooks.
- Place names and pub names — the White Hart is one of the most common inn names in England.
- Surnames, and the antelope name hartebeest.
In ordinary modern writing about wildlife, most people say stag.
The test
Ask a single question: is this sentence about a deer? If not — and it almost never is — write heart. There is no borderline case where both are plausible, which makes this one of the easier confusions to eliminate once you know the word exists.
What to watch for
Because the words are homophones in effectively all accents, dictation software and voice typing will sometimes choose hart, especially if a surname of that spelling is in your contacts. Proofreading by eye catches it; automatic tools generally will not.
Two related lookalikes are worth keeping separate. Hearth, with the extra h, is the floor of a fireplace — "a cat asleep on the hearth" — and rhymes with earth rather than heart. And heartily means with enthusiasm ("he laughed heartily"), while heartfelt means sincere; both belong to heart and neither has a hart equivalent.
Frequently Asked Questions
Is "hart" still a word people use?
It is still listed in dictionaries and still appears in poetry, heraldry, place names and pub names, but it has largely been replaced by "stag" in ordinary writing about deer.
Is it "learn by hart" or "learn by heart"?
"Learn by heart", meaning to memorise. Every idiom in this family — take heart, lose heart, know by heart — uses the organ, never the deer.
What's the difference between heart and hearth?
A hearth is the stone or brick floor in front of a fireplace. It is a different word with a different sound, rhyming with "earth", though the spelling similarity catches people out.