keen
n.n. wanting to do something very much or being very interested in an activity. You can also use it to describe a sharp mind or a very strong sense, like smell.
n. demonstrating an intense desire or enthusiasm for an activity; also used to describe sharp intellectual perception or highly developed physical senses.
She is a keen gardener and spends every weekend outside.
The company is keen to hire new graduates who show a strong work ethic and a willingness to learn.
Despite his age, the professor retained a keen intellect and an uncanny ability to spot logical fallacies in his students' arguments.
When expressing enthusiasm, it is often followed by 'on' plus a noun or gerund, or by a 'to' infinitive.
He is keen for playing footballHe is keen on playing footballWhen followed by an -ing verb to show interest, use the preposition 'on' rather than 'for'.