Sole means <em>only</em>, and also names the underside of a foot or shoe: <em>She was the sole survivor</em>; <em>The sole of my boot has worn through.</em> Soul means the spirit or inner self, and the music genre: <em>He sang with real soul.</em> If <em>only</em> fits the slot, write sole; if the sentence is about a person's inner life, write soul.
The core difference
These are homophones — identical in sound, unrelated in meaning — and both are ordinary words, so a spellchecker will never catch the swap.
Sole covers three senses: the adjective meaning only or exclusive; the noun for the flat underside of a foot or shoe; and the flatfish served in restaurants.
Soul is the immaterial part of a person — spirit, character, deep feeling — plus the genre of music that takes its name from that idea.
How to use each
- She has sole responsibility for the accounts. (only)
- The company is the sole supplier in the region.
- Sand had got into the sole of his trainer.
- The village was empty — not a soul in sight.
- The record has more soul than anything they've released since.
A test you can run
Try replacing the word with only. The only survivor, only responsibility, the only supplier — all work, so all take sole. If only makes no sense, ask whether spirit or person fits instead; if so, you want soul.
The memory trick
S-O-U-L has a U in it, and it is about yo-u — the inner you. Everything else is sole.
The traps to watch
Two idioms cause most of the errors:
- Not a soul means "nobody at all". Soul here is a countable word for a person — the same use as the ship went down with 300 souls aboard. Writing "not a sole" is a common slip.
- Heart and soul, soul-searching, bless my soul — all take the U.
Going the other way, sole trader (a business owned by one person), sole custody, sole agent and sole discretion all mean "only", so all take the E. These appear constantly in contracts, where the wrong spelling looks careless.
Note too that sole is a verb in shoemaking: the boots were re-soled. And the fish takes no article change — grilled sole, lemon sole — so if the sentence is about dinner, it is the E spelling.
The near-miss: solely
The adverb from sole is solely, meaning "only": The delay was solely due to weather. There is no adverb "souly", so if you have written an -ly form, the base word was sole.
Frequently Asked Questions
Is it "sole survivor" or "soul survivor"?
<em>Sole survivor</em> — the only one who lived. <em>Soul Survivor</em> appears as a title of songs and events, where the pun is intentional, but in ordinary writing it is always sole.
Is it "not a sole" or "not a soul"?
<em>Not a soul</em>, meaning not a single person. <em>Soul</em> has long been used to count people, as in <em>a village of 200 souls</em>.
Which one is the bottom of a shoe?
The <em>sole</em>, same spelling as the word meaning only. The verb form follows: shoes get <em>re-soled</em>.