What is a root word?

What is a root word?
We explain what a root word is and how prefixes and suffixes can be added to root words turn them into words with different meanings.

What is a root word?

A root word is a basic word with no prefix or suffix added to it (a prefix is a string of letters that go at the start of a word; a suffix is a string of letters that go at the end of a word). By adding prefixes and suffixes to a root word we can change its meaning.

The suffixes -er and -est are also used to form the comparative and superlative of adjectives (for example, light / lighter / lightest).

For example:

The root word astro could have the suffix -nomy added to it to make the word astronomy.

'Astro' means 'stars' and 'nomy' means the study of something. Astronomy is the study and knowledge of stars.

The root word lingual could have the prefix bi- added to it to make the word bilingual.

'Bi' means two and 'lingual' means pertaining to language. Someone who is bilingual is fluent in two languages.

Some root words can have both prefixes and suffixes attached to them to turn them into words with different meanings:

Root word With a prefix added With a suffix added
normal abnormal normality, normalise
might almighty mightily
education co-education educational, educationally
legal illegal legalise, legality
mature immature maturity
behave misbehave behaviour, behaved
fiction non-fiction fictional, fictionally
dress undress dressed
happy unhappy happier, happily

Children learn a range of words with suffixes and prefixes throughout their time at primary school, usually starting in Year 2 and Year 3.

Often, children will be given a list of spellings to learn at home that all have the same suffix, or all have the same prefix.

It is a good idea for them to be aware of root words, as learning one root word (for example: education), will then help them to spell other words containing that word such as co-education and educational.

Learning root words, suffixes and prefixes also helps children to understand words better, as they begin to see links between different words and identify word families.