<em> Quotation marks </em>are used for several puposes such as nicknames, translations, measurements etc. One use is to give a word or a sentence a s<em>cary or serious meaning or to emphazise that the word is being used as an</em> <em>euphemism or </em> <em>for terms used in an unusual way or for technical terms</em>. For sarcasm the proper use is of <em>single quotation marks.</em>