I'm going to tell you something that you can't actually learn. Well, you can learn it, there's

just no rules for it. I'm talking about specifically some prefixes.

"Dis-", "un", "in/im-/il/ir-", "non-". Okay?

First of all, let's review a little bit. What is a prefix? A prefix is a little part of

a word that comes before the main word; can come before an adjective, before an adverb,

before a noun, before a verb. Anything that comes before a word, especially before a root

of a word. We're going to look at an example of that very soon.

So, I was asked specifically to talk about these prefixes. All of them basically mean "not".

Okay? They negate the word they are added to. Now, generally speaking, you can

find specific little subtle differences between all of them. For example, "dis" means more

like be apart of or away from, separate. "Un" means not or a reversal of something,

or not having something, a lack of something, a deprivation. And same with these guys, not,

reverse, opposite. "Non" is the most simple one. "Non" basically means not. Okay?

But, the problem is that most of these can go with many words, but there's no real rule about

which word takes which prefix. Okay? So, how do you learn which one to use in which situation?

Well, I'll tell you after we look at a few examples. Okay?

So, again, all of these mean not. The only thing you have to worry about the most is

the actual word that is being connected to a prefix. Okay? Concentrate on the root or

the word itself before you concentrate on which prefix to join to it.

Now, you will see that some words will take both prefixes, and be totally okay.

The problem is that their meanings are completely different. So, "to dislike", this is a verb,

"to dislike", it could also be a noun. "I have a strong dislike for certain vegetables", for example.

But "to dislike" means to not like. Now, if you say: "I don't like Pizza."

And you say: "I dislike Pizza." These are a little bit different. Right? "Don't like"

or "not like" means you don't have a good feeling towards. But "dislike" means you actually

have a bad feeling towards. Right? So, this is a little bit more active. You're away from liking it.

You're actually having a bad feeling for it. "Unlike" has absolutely no connection

to "dislike". "Unlike" means not similar to. This is the preposition "like", "A" is like "B".

This is the verb "like", means to have a good feeling toward. So, concentrate on

the word you have. You have the verb, you have the preposition, and then decide which

prefix you want to join to it.

So, here, I have a few examples of words that can take two prefixes and have different meanings.

So, for example: "discover" and "uncover" are two completely different verbs. "To discover"

means to find by accident. You're walking along the beach, and you discover the skull,

the bone... Head bone of a dinosaur. You didn't look for it. You just found it. Okay?

You discovered it. So, it was hidden by nature, by time, and then you took away the cover

and there it is, the skull. "Uncover", on the other hand, means you were looking for

something and you found it.

So, you're a... I'm a reporter. I work for a major newspaper, and I think that this particular

politician is corrupt; he's lying to the people, he's stealing their money. So, I investigate.

And after my investigation, I uncover certain facts that will help the police put him in

jail. Not, not, not covered, not covered, means not hidden, but this one by accident,

time, nature hit it, I, by accident discovered it; "uncover" means I looked for, I found.

This one, or these two, I should say: "disinterested" and "uninterested". These are always mixed

up. You cannot use these two interchangeably; you have to use one or the other. I'll start

with "uninterested". ''Uninterested'' means indifferent, don't care. It's boring. I'm uninterested.

I don't want to know. Leave me alone. "Disinterested" means impartial, means you're not... You don't

have a reason to take one side or the other. Okay? So, again, I'm the reporter. I have

nothing to gain or lose by finding out information about this politician. I am a disinterested

party. I am objective. Okay? I am not involved in the situation. I'm just reporting the facts.

Here, I don't care; here, I'm not part of the situation.

Now, you also think: "Well, these two are kind of weird. There are two different words here."

Right? But you have a "discomfort", you are "uncomfortable". That's a little strange.

This is a noun, this is an adjective. You go to the doctor, you complain of a discomfort in your side.

But if you sit and somebody left a pen on your chair, oh, a little uncomfortable.

You're not... You know, you want to get up and see what's going on there. A discomfort

is like a real thing, probably inside. Uncomfortable, you can fix somehow.

"Disable", okay? We're going to look at the verb, "disable". Means make not able. Take

away the ability of something. So, you have a machine running. You think: "Oh, it's a

little bit dangerous." You don't want anybody to use it, so you disable it. You disconnect

the fuse. Now, nobody can come and use this machine. It has been disabled. We say about

a person if he or she is disabled, usually they're in a wheelchair, they had an accident

or they were born with a problem. They are not able. "Unable" means can't. I am unable

to help you because I just don't know. Okay? "Unable", "disable".

We're going to come back to this bottom one, here. So, that's a few things. Oh, a couple

more. "Disorganized", "unorganized". Usually, you would say about a person: "He or she is

disorganized." He has things everywhere or she has things everywhere; it's a big mess.

But the office or the room of this person is unorganized. So, we talk about an organization,

or a company, or an association, or a place that is unorganized. We talk about a person

being disorganized. I'm going to come back to these.

So, now, we know, "dis", "un", depends on the word you're using. Same goes for these

ones. Right? For example, "non", "non", there are not that many words. You have a "nonpayment".

Okay? You bought something, it's non-refundable. Keep in mind sometimes you will have a hyphen,

sometimes you will not. How do you know? Check the dictionary. Again, not really any rule

here. Some dictionaries, like American dictionaries will put like a hyphen, British ones won't.

Depends what you need, that's what you'll use.

"In", "im", same thing, especially with "il", "ir", they're all exact same. They also mean

not, or opposite, or lack. We usually use "im" with words that begin with a "b", "m",

or a "p". Now, the thing about "in" or "im", you have to be careful about it. They don't

only mean not; they have other meanings. For example, it could mean to put something into,

or show direction towards the inside of something. Right?

So, for example, "immigrate" means migrate into a country. So, come... Or come into a

country, I should say, sorry. "Migrate" move, "im", into. Move into a country. "Inflame",

so this is another use of the prefix "in". Means to cause, to be, or to make. Right?

So, you inflame, you make it... The flame, you make it more of a flame, you intensify it.

Sorry, intensify. So, there's a... Somebody's having a fight, you want to inflame it. You

give them both reasons to fight more. You inflame the product, the situation. So, "in"

and "im" not only mean "not", they also mean "toward" or "to cause". So, be careful.

"Il" and "ir" we use with words that begin with "l" or "r". For example, "illogical",

"irrelevant". Going back to "im", "b", "m", "p". "Imbalanced", "immaterial", "impossible".

I'm using adjectives. You're not limited to adjectives. There could be other things. For

example, "immigration" is a noun. "Immigrate" is a verb. I'm still using the "im". So be

careful about these. And the "non", "nonpayment", "non-refundable".

Now, there is another situation. "Mis", I know this is not on my list, this is a different

prefix. But many people think that "mis" means "not". It doesn't. "Mis" means wrongly, in

a wrong way. So, "inappropriate" means not appropriate, not proper, not correct. "Misapproriate",

"inappropriate", "misappropriate", this word and this word are two different words. This

is an adjective, means correct or proper. "Appropriate" is a verb, means take. If you

misappropriate, you take something in a dishonest way, in a wrong way. Okay? So, be very careful

about "mis". And make sure you understand which word you are using before you add your prefix.

Now, we're getting to the gist of the lesson, we're getting to the main point. How do you

know, and what if you don't know which prefix to use? So, for example, "unsecure", "insecure".

"Insecure" generally, we talk about a person... A person's attitude toward him or herself.

If someone is insecure, means they lack confidence; they're not confident. They don't have the

self-security. "Unsecure" means not safe. Now, if you're talking about a computer that

doesn't have an anti-virus, it's unsecure. It doesn't have a firewall, it's unsecure.

If you attach a picture to the wall... For example, this, this whiteboard is secured

to the wall. If I take out the screws, it might fall over, it would be unsecure.

But many people feel this word is uncomfortable, it just doesn't sound right, "unsecure". If

you're not sure, use the two words. Say: "Not secure". If this word, "unsecure" doesn't

feel correct, don't use it. Use "not secure". Tell me the meaning of this. Okay? Don't worry

about the word itself if you don't like it.

Which, brings us, again, to the main point: how do you know? Well, you have to feel.

You have to feel the language, you have to feel which word sounds correct or not. Now, this

is especially important in writing. In spoken English, if you say: "Dispossible", people

will look at you a little bit strange, but they will understand what you're saying. In

writing, they will look at it and try to figure out what's going on; they'll get confused.

In writing, it's very important to use the right word, the correct word. You have to feel it.

Now, how do you feel which word is correct and which word is not? Read. Read a lot, a

lot, a lot, a lot. This is where you get to feel the language. For example, if you read

100 books by 100 different authors, all of them will use "imbalanced". Nobody will use

"disbalanced". Some might use "unbalanced". Okay? So, you're free to use one or the other.

Okay? "Immaterial", everybody will use "immaterial" or "not material". "Immaterial", by the way,

means not important, not relevant. Same as "irrelevant", "immaterial", synonyms. Okay?

So, now, personally, I recommend reading novels. Why? Because the authors of novels, technically,

should have a very strong command of grammar. They spend a lot of time thinking about every

word they use, and they have editors, who also check every word they use. So, novels

get you... Really play with the language and really help you get this feel for the language.

But until you get that feeling, until that time comes, use a dictionary. Like anything

else, if you're not sure, check. The dictionary says like this, use it like that. If you're

in the middle of the test and you can't think of... You don't have a dictionary, you have

to write something, give it your best guess and hope for the best. But eventually, you

will know just by looking at it if it's right or wrong.

Okay, if you go to www.engvid.com, I put a quiz there that will test your knowledge of

some of these words with their prefixes. A couple little surprise ones for you as well.

Also, don't forget to subscribe to my channel on YouTube. And ask any questions you'd like,

and I'll get back to you as soon as I can. Thanks.