Inform of, on, about, or by? Here’s the correct preposition (+20 Examples)

Prepositions following words can make for a challenge for anyone new to English or learning grammar rules. Let’s take the word “informed,” for example. There seem to be many prepositions that might follow it. Is it informed of or on, informed of or about, or something else?

Should I Use Inform Of, Inform On, Inform About, Or Inform By?

You should use inform of when you are referring to one person being told information from another person. You should use inform on when we are given evidence or telling someone information about illegal activity. You should use inform about in the same way as inform of, but often it is implied that more details are included in the explanation. You should use inform by in the passive voice when including the agent that informed you.

When Should I Use Inform Of?

Let’s start with inform of, then and look a little deeper. As we said, “inform of” is one of the four main ways to use the term “inform” with a preposition. We use it when we tell someone information, though it doesn’t often come with much more detail. Usually, we’ll inform someone of an event so that they know that the event has occurred, rather than what might have happened within the event.

5 Examples Of How To Use Inform Of

• We need to inform him of the schedule.
• He informed me of his decision yesterday.
• Will you inform me of your choice when you know?
• It would help if you kept informed of current trends.
• Am I informed of all I need to know?

As you can see from most of these sentences, the idea is only to “inform” someone of information. There is no strict need to tell them the bare minimum, and usually only what the event or trends are.

When Should I Use Inform On?

We use inform on when we are given evidence or “telling on” someone. It’s not often used in any other scenarios, which is why we associate it so closely with the legal system over everything else. You’ll often find “informants” in legal offices (or more commonly in film and tv) who are only working with the police to “inform on” the misdemeanors of their contacts.

5 Examples Of How To Use Inform On

• He informed the state on the gang’s activities.
• She informed us on her former boss’s habits.
• The police recruited him to inform on the local gang.
• I was recruited to inform on my fellow gang members.
• We were informed on this matter.

These examples all rather to somebody telling somebody else about crimes or misdemeanors, as this is the only acceptable use of “inform on.”

When Should I Use Inform About?

Now let’s look at inform about. We use inform of or about in much the same way. They’re both designed to deliver information from one person to another, though with “inform about,” it’s implied that more information will be presented. You can still say to “inform about” an event, but generally, you would inform the person and tell them more information regarding the event to work with more knowledge.

5 Examples Of How To Use Inform About

• You need to inform him about the meeting.
• Would you mind informing me about what happened last night?
• Keep me informed about all decisions made over dinner.
• I informed the employees about all the new policies.
• We were informed about what happened.

Unlike “inform of,” there’s an implication here that more details will be present for the listener when they are informed. It’s not something that’s made clear, but it is something you will learn over time when you start using “inform about” in the right contexts.

When Should I Use Inform By?

Finally, let’s look at the last preposition that might follow “inform.” We use “inform by” when talking about somebody else informing us (or someone else) about the information. It’s often used in a different tense but means the same thing as both “inform of” and “inform about.” It uses the passive voice to talk about who informed who about the information.

5 Examples Of How To Use Inform By

• I was informed by my mom earlier today.
• He was informed by his boss that he has one week left.
• We were informed by our neighbors that we had to leave.
• She was informed by her father.
• I was informed by the teacher.

In all of these examples, you’ll notice that we’re talking about “inform by” in the past tense. The words “was” or “were” always precede it to indicate this. The reason for this is because we can’t use “inform by” in the present tense. After all, there’s no way that anyone is currently informing by us. The word “by” shows a past tense to the phrase, so you can only use it in the past tense and passive voice.

When Should I Use Inform Without A Preposition?

The word “inform” itself is known as a transitive verb. This means that a direct object is needed for it to make any grammatical sense in a sentence. Other verbs follow this same trend; for example, you wouldn’t be able to say “I like” without including an object at the end to say what you do “like.” If you just used “I like” as a sentence, people would often question your understanding of the language.

So, the same transitive rules apply to “inform,” which means you always need an object following it. That’s why so many prepositions can follow it, but you’ll notice that each preposition, no matter the sentence, still required an object in the sentences to do the informing. So, without a preposition, let’s look at a few final examples of how we can use inform.

• I inform Peter daily.
• She informed me.
• We inform our mom.
• You can’t inform him.
• The boss informed the employee.

There’s a direct object after “inform,” whether it’s a name, pronoun, or another noun in each of these cases. Without it, there would be no grammatical correctness to the sentence.