verb
/ˈtiːʧ/ teaches; taught /ˈtɑːt/; teaching
to cause or help (someone) to learn about a subject by giving lessons [+ obj]
[+ obj] :to give lessons about (a particular subject) to a person or group
[+ obj] :to cause or help (a person or animal) to learn how to do something by giving lessons, showing how it is done, etc.
[+ obj] :to show someone how to behave, think, etc.
[+ obj] informal :to cause (someone) to know the unpleasant results of something
you can't teach an old dog new tricks