Un is a prefix meaning not. It's used to give opposite and negative meanings to adjectives, adverbs and nouns.
Root word: Able.
Meaning: To not be able to do something.
Example: She's unable to attend tomorrow's meeting.
Root word: Aware.
Meaning: To not know something.
Example: I was unaware the plans had changed.
Root word: Beat.
Meaning: To not have lost any games.
Example: In 2004, Arsenal went the whole football season unbeaten.
Root word: Common.
Meaning: Unusual or rare.
Example: Because the public transport system is so good, it's uncommon for me to drive to work.
Root word: Dress.
Meaning: To take off clothes.
Example: Get undressed and get into the shower.
Root word: Employ.
Meaning: The number of people who do not have jobs.
Example: The government reported a small decrease in the unemployment rate.
Root word: Fair.
Meaning: Not equal or not right.
Example: It's unfair to ask James to work late again.
Root word: Fit.
Meaning: Not healthy or not good enough.
Example: I'm too unfit to play tennis with you.
Root word: Miss.
Meaning: So good that it must be seen.
Example: She described the film as unmissable.
Root word: Rely.
Meaning: Can't be trusted or depended on.
Example: He's totally unreliable, I wouldn't ask him for help.
Now take a look at these sentences and decide which un- words are needed:
