Inform vs. Notify vs. Brief

In English, when you want to tell someone about something officially or formally, you can use the following words:

Inform
Inform someone : When he arrived, inform me immediately.
Inform someone of/about : Why didn't you inform me of his arrival/death
Inform someone that: She informed me that she had not changed her plans.
Well- informed:He was never dull, always erudite and well-informed.

Notice that inform must have a direct object :
He informed me that he would not be able to come.
Don't say: He formed that he would never come.

Notify :
Notify is more formal than inform.

Notify someone:They were expected to notify us when they changed their plans.
Notify someone of/about : The company notified us of /about the inauguration date of its new system.

Brief
The verb means to give someone all the necessary information or instructions you need about a situation/a serious matter/a piece of work,before you do it or consider it.

- He briefed the new spies about/on their mission.
- We had already been briefed about/on what the job would entail.
- The Prime Minister has been briefed by her parliamentary aids.

Tell vs. Let someone know vs. Put someone onto

The verbs and expressions mean to give someone facts or information by speaking to them or writing to them.

Tell
- I told him I got a raise yesterday.
- My father told me all the details of my mother's death.
- She didn't tell me where she was going to go.


Let someone know
To tell someone something/some information.

Let some one know something - Let me know your new address.
Let someone know if/whether- Please let me know if/whether you decid to leave.
Let someone know (that)- When he left the country for ever, I let his mother know that he would never come back.
Let someone know where/what/when/why...- Her brother tried to let her know why he changed his mind.Let him know when you buy the cay.

Put someone onto
To introduce a person to something or someone that could bring them an advantage or an useful thing.

- David put me onto a wonderful vegetarian cookery book.
- Can you put me onto (= tell me where to find) a good dentist?
- The elastic is a powerful varity which a friend in the clothing trade put me onto.