Mature is an adjective or a verb: "she is very mature for fifteen", "the wine matures in oak". Maturity is the noun naming the quality or the state itself: "she handled it with real maturity". If you can put "great" in front of it, you need maturity.
The core difference
These are not rival words; they are two forms of the same word doing different grammatical jobs. Mature describes something (adjective) or says what it does (verb). Maturity names the thing itself (noun). Choosing between them is a question of sentence structure, not meaning.
Mature as an adjective
It sits before a noun or after a linking verb such as be, seem or become:
- He's remarkably mature for his age.
- A mature oak can drink hundreds of litres a day.
- The university welcomes mature students.
Mature as a verb
Here it means to develop fully, or, in finance, to reach the date when payment falls due:
- The cheese matures for eighteen months in the cave.
- His writing matured noticeably after the second novel.
- The bond matures in 2031.
Maturity as a noun
It follows articles, possessives, adjectives and prepositions:
- She showed extraordinary maturity in the interview.
- Salmon reach maturity after several years at sea.
- The policy pays out on maturity.
The test
Try putting "great" in front of the word. If "great ___" sounds right, you need the noun, maturity — "great maturity" ✓, "great mature" ✗. If instead the word is describing a person or thing — you could swap in "grown-up", "ripe" or "fully developed" — you need mature. Do not use "the" as the cue: it sits happily in front of the adjective too, in "the mature students" and "the mature oak".
A second check: after is, are, was or seems, describing someone, use the adjective. "He is mature" ✓, not "he is maturity" ✗. But "he is the picture of maturity" ✓, because a preposition now demands a noun.
Where the error actually shows up
Almost always in praise: "she has a lot of mature" or "he showed great mature". After a lot of, great, this level of or such, the noun is required — maturity. The mirror error, "a very maturity student", is rarer but comes from the same gap.
The rest of the family
- maturely (adverb): "he responded maturely to the criticism".
- immature / immaturity: the negatives follow the same split.
- maturation: the process of maturing, used mainly in biology and technical writing — "the maturation of the eggs takes ten days". Prefer maturity for the state, maturation for the process.
A quick note on the finance sense
In banking, maturity is the date a loan, bond or savings product falls due, and mature is the verb for reaching it. "A five-year maturity" and "the deposit matures in May" both use the standard split — nothing special to learn.
Frequently Asked Questions
Is it "he showed great mature" or "great maturity"?
Great maturity. After great, a lot of, or such, English needs a noun, and maturity is the noun form. Mature can only be an adjective or a verb.
What is the adverb form?
Maturely. "She dealt with it maturely" describes how the action was done, whereas "she dealt with it with maturity" uses the noun after a preposition. Both are correct.
What's the difference between maturity and maturation?
Maturity is the state of being fully developed; maturation is the process of getting there. Maturation is largely confined to scientific and technical writing.