Recently I came across this fabulous chart of colorful idioms on <a href="http://www.grammar.net/colorfulidioms" target="_blank">Grammar.net</a> Great site, btw,  if you're grammatically challenged like me.

<a href="http://judythewriter.files.wordpress.com/2013/09/10-colour-idioms_big-01.png"><img class="alignleft size-full wp-image-3602" alt="10-colour-idioms_big-01" src="http://judythewriter.files.wordpress.com/2013/09/10-colour-idioms_big-01.png" width="500" height="1857" /></a>

Technically, an <a href="http://dictionary.reference.com/browse/idiom?s=t" target="_blank">idiom is a word or phrase that is not taken literally</a>. Languages are loaded with idioms.

The expressions are global and the same idiom can have a very different meaning in a different country. In Finnish, “<i>with long teeth</i>” means you are doing something that you really don’t want to do. Same phrase in French, “<i>to have long teeth</i>” means you are ambitious.

Groups of people with shared/common interests have their own idioms. Think about these examples from music and drama:
<ul>
	<li>“It’s not over ‘till the fat lady sings.”</li>
	<li>“Break a leg”</li>
	<li>“It takes two to tango”</li>
</ul>
When I taught English as a Second Language, idioms challenged my  students. Common idioms, like the examples below, were easy to teach.
<ul>
	<li>A chip on your shoulder</li>
	<li>High as a kite</li>
	<li>Sick as a  dog</li>
	<li>Rub someone the wrong way</li>
	<li>Jump the gun</li>
	<li>Pay the piper</li>
</ul>
When the students conversed with their fellow native speaking friends, other not so common expressions managed to stump them.

Signing idioms when I was interpreting for the deaf was a tough call, too. I had to know what the speaker meant. Sometimes I didn’t!

Usually it’s easy to pick up the meaning from the context of the conversation or non-verbal gestures. Sometimes it’s best to ask exactly what the speaker means.

If you're not sure what the idiom examples I've used mean, here’s a site that defines common idioms: <a href="http://www.idiomsite.com/">http://www.idiomsite.com/</a>

Idioms can complicate speaking and writing. I advise using them sparingly…unless your meaning is clear!