Prefixes

What is a prefix?

A prefix is a group of letters which you can add to the beginning of a root word* to change the meaning of the word. e.g. mis + fortune = misfortune

*A root word stands on its own as a word but you can make new words from it by adding beginnings (prefixes) and endings (suffixes).
For example, 'comfort' is a root word. By adding the prefix 'dis' and the suffix 'able' you can make new words such as 'discomfort' and 'comfortable'.

Prefix meanings:
Every prefix has a meaning, for example:
The prefix 'un' means 'not'
The root word 'clear' means 'bright', 'free from difficulty'

un + clear = unclear which means 'not clear' or 'dim', 'difficult to see or understand'

There are no rules to help you remember which prefix you should use, although knowing the meaning of the prefix can help.
Here are some examples of prefixes and their meanings...

Prefix	Meaning
mis	means 'wrong' or 'badly' e.g. 'misspelled' or misspelt means 'wrongly spelled'
sub	means under e.g. 'subway' means 'a way under the ground'
pre	means 'before in time', 'in front of' or 'superior' e.g. 'prepacked' means 'packed before'
un	means not (there are also several other prefixes which mean not) e.g. 'unhurt' means 'not hurt'

Adding prefixes to root words

1. Generally when you add a prefix to a root word* the spelling of the prefix and the root words stays the same.

*A root word stands on its own as a word but you can make new words from it by adding beginnings (prefixes) and endings (suffixes).

Prefix	+	Root word	=	Word
un	+	kind	=	unkind
im	+	mature	=	immature
bi	+	cycle	=	bicycle
mis	+	fire	=	misfire
in	+	visible	=	invisible

Exceptions
When you add a prefix to a root word the spelling of both usually stays the same, although when the prefix 'all' is added to a root word the final 'l' of 'all' is dropped.

all + together = altogether
all + ways = always

2. With some root words more than one type of prefix may be added to give the word different meanings.

Prefix	+	Root word	=	Word
dis	+	appear	=	disappear - means to no longer appear, or cease to appear
re	+	appear	=	reappear - means to appear again

3. Sometimes you can add more than one prefix to a word at the same time.

Prefix	+	Prefix	+	Root word	=	Word
re	+	dis	+	cover	=	rediscover

4. You can also add a prefix to a word which already has a suffix* added to it.

*A suffix is a group of letters that you add to the end of a root word.

Prefix	+	Root word	+	Suffix	=	Word
re	+	play	+	ing	=	replaying
un	+	want	+	ed	=	unwanted

Prefixes meaning 'not'

There are several prefixes which reverse the meaning of a word. An easier way to remember them is if you think of them to essentially mean 'not'.

Prefix	Meaning
un	means not e.g. 'unhurt' means 'not hurt'
im	means not e.g. 'impolite' means 'not polite'
il	means not e.g. 'illegal' means 'not legal'
in	means not e.g. 'informal' means 'not formal'
ir	means not e.g.'irregular' means 'not regular'
dis *	one of the meanings of this prefix is also 'not' e.g. 'disagree' means 'not agree'

Other prefixes

Here are some other examples of common prefixes for you to learn.

Prefix	Meaning
dis	means away, apart, between, utterly (when used with a negative word) and not. e.g. 'disarm' means to remove or take weapons away
mis	means 'wrong' or 'badly' e.g. 'misfortune' is when your are not lucky and things go wrong or badly
under	means 'below' or 'beneath' e.g. 'underground' means below or beneath the ground
over	means upper, outer, over, superior or excessive e.g. 'overweight' means too heavy or fat
re	means again e.g. 'replay' means to play something again
trans	means across or through e.g. 'transatlantic' means across the Atlantic ocean
inter	means among, between or together e.g. 'intermission' is the short period of time between the parts in a performance or a film
super	means in excess, beyond e.g. 'supersonic' means faster or beyond the speed of sound
anti	means against, in opposition to e.g. 'anticlockwise' is opposite to the direction that the hands of a clock move in
ante	means before e.g. 'antenatal' means before giving birth
post	means after e.g. 'postpone' means to put something off until later, or after it was originally planned

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