Which is correct, atypical or untypical?

Question

Onder from Brazil asked which is correct, atypical or untypical? Many people are confused by these two words. Below is a response to another user who asked the same question last November.

Answer

Which is correct, atypical or untypical? (Monday, November 28, 2011)

Because the prefixes a- and un- can both mean not, atypical and untypical have the same meaning: not typical, not usual or normal. However, the contexts in which these two words are used are different. There is also a 3rd choice with the same meaning, which will be discussed below.

Atypical

Atypical is the most common of these choices. It is used mostly in formal language about medical topics, as in these examples:

• These cases were atypical because the patients were diabetic.
• The biopsy showed a few atypical cells.

Untypical

Untypical is used less often then atypical, and it is becoming rarer still. When untypical is used, it is most often after the word not, as in this example:

• The summer weather arrived suddenly, which is not untypical for New Orleans.    (not + untypical = typical)

Not typical

The phrase not typical is used more than untypical. Not typical can be used in a variety of contexts to talk about all kinds of topics, as shown in these examples:

• This was not typical behavior for a 10-year-old.
• It was not a typical business meeting.
• This is not typical weather for Miami.

I hope this helps.