Using Prefixes and Suffixes

You already know that word parts can change a word's meaning. Now you will learn more prefixes and suffixes, and you will use them to figure out what a whole word means. This helps you read new words on your own, even in longer books.

A prefix is a word part added to the front of a word. A suffix is a word part added to the end of a word. The middle part is called the root word. When you find all three parts, you can often guess what the word means.

Look at the word "unhelpful." It has three parts: the prefix "un-," the root "help," and the suffix "-ful."

Here are prefixes that show up in many words. Each one has its own meaning.

Suffixes come at the end of a word. They can tell you how many, when something happens, or what kind of thing a word describes.

When you see a word you do not know, try these steps.

1. Look at the start of the word. Is there a prefix, like "un-" or "re-"?
2. Look at the end of the word. Is there a suffix, like "-ful" or "-less"?
3. Find the root word that is left in the middle.
4. Think about what each part means.
5. Put the meanings together to guess the meaning of the whole word.
6. Read the word in its sentence to check if your guess makes sense.

Look at how the word "careless" breaks into a root and a suffix. The root "care" means to look after something. The suffix "-less" means without. So "careless" means without care.

Now try "unhelpful." It has a prefix, a root, and a suffix: "un-" means not, "help" means to help, and "-ful" means full of. Put the parts together and "unhelpful" means not full of help.

One more example is "reusable." The prefix "re-" means again, the root "use" means to use something, and the suffix "-able" means can be. So "reusable" means can be used again, like a water bottle you fill up over and over.

Prefix: A word part added to the front of a word that changes its meaning, like "un-" or "re-."

Suffix: A word part added to the end of a word that changes its meaning, like "-er" or "-less."

Root Word: The main part of a word that is left after you remove the prefix and suffix.

Decode: To figure out what a word means by looking closely at its parts.

Careless: Without care; the root "care" plus the suffix "-less."

Unhelpful: Not full of help; the prefix "un-," the root "help," and the suffix "-ful."

Reusable: Can be used again; the prefix "re-," the root "use," and the suffix "-able."

Look through a book for words with "dis-" or "mis-" at the start. Cover up the prefix and read the root word by itself first, then add the prefix back.

Pick a root word like "kind" or "play" and add different suffixes to it, such as "-ness," "-ful," or "-ing." Say each new word out loud and think about how the meaning changes.

Related lessons

• Decoding Words Using Affixes