inform (one) about (something)

To share information about something with one. Have you informed Phil about the time change for Saturday's dinner? Don't worry, I'll inform the investors about your illness, and we'll reschedule the meeting. Please don't inform anyone about the boss's accident. I need to get more information about it myself and don't want people gossiping about him in the meantime.

inform (one) of (something)

To share information about something with one. Have you informed Phil of the time change for Saturday's dinner? Don't worry, I'll inform the investors of your illness, and we'll reschedule the meeting. Please don't inform anyone of the boss's accident. I need to get more information about it myself and don't want people gossiping about him in the meantime.

inform against (one)

To share or reveal compromising or incriminating information about one, especially to the police or other figures of authority. If you inform against him to the cops, he'll definitely send some of his goons out after you. Yeah, I know about your shady deals, but I didn't inform against you, I swear! My life is at stake here! How can I convince the mob boss that I didn't inform against him?

inform on (one)

To share or reveal compromising or incriminating information about one, especially to the police or other figures of authority. If you inform on him to the cops, he'll definitely send some of his goons out after you. Yeah, I know about your shady deals, but I didn't inform on you, I swear! My life is at stake here! How can I convince the mob boss that I didn't inform on him?