Usage patterns
〈事〉に興味があるto be interested in ~
I'm interested in history.
〈事〉に興味を示すto show interest in ~
The child showed interest in the new toy.
興味が湧くfor interest to arise; to become interested
After watching that movie, I became interested in Japanese culture.
興味を失うto lose interest
He quickly lost interest.
〈事〉への興味interest in ~ (as a noun phrase)
My interest in science deepens every year.
Expressions
興味ないuninterested; not interested; having no interest 興味を引くattract interest; arouse curiosity; catch one's attention 興味を持つhave an interest (in); be interested (in) 興味をそそるarouse interest; whet the appetite; be intriguing