Myriora English › Words › Chapter 1: Building words: prefixes, suffixes and roots

Opposite-making prefixes

Ages 9–11Chapter 1 · Lesson 8

In this lesson

I, L before L, and I, R before R.
I, M before M or P.
I, N for lots of other words.
And keep both letters when they double!

Your turn

What's the opposite of mature?

Show the answer

Immature! Mature begins with M, so we use I, M, and that gives two Ms.

The common mistake

Here's a common mistake. Lots of people spell irresponsible with just one R. But it's I, R, plus responsible, so there are two Rs.

Try it at home

Opposite chain: take turns saying a word (polite, legal, regular, correct) while the other says its opposite with the right prefix and spells it, keeping any double letters.

Read the whole lesson

Hello, and welcome to Myriora English! To make the opposite of some words, we add a prefix that means not. Possible becomes impossible. Legal becomes illegal. But how do you know which prefix to use?

Here's a handy rule. Before a word beginning with L, use I, L: illegal. Before R, use I, R: irregular. Before M or P, use I, M: immature, impossible. And for lots of other words, it's I, N: incorrect, invisible.

Look what happens to the spelling. I, L, plus legal, gives two Ls: illegal. I, R, plus regular, gives two Rs: irregular. Keep every letter from both parts!

Let's try one together. What's the opposite of polite? Say it out loud!

Impolite! Polite begins with P, so the prefix is I, M. Well done if you said impolite!

Here's a common mistake. Lots of people spell irresponsible with just one R. But it's I, R, plus responsible, so there are two Rs.

Your turn! What's the opposite of mature? Pick the right card. You've got eight seconds, or pause the video. Go!

Time's up! Immature! Mature begins with M, so we use I, M, and that gives two Ms.

Quick review. I, L before L, and I, R before R. I, M before M or P. I, N for lots of other words. And keep both letters when they double! See you next time!