Image caption Teenage slang - do I not like that?

Actress Emma Thompson says young people make themselves sound stupid by speaking slang outside of school. But while the use of the word "like" might annoy her, it fulfils a useful role in everyday speech.

"That's, like, so unfair."

One response to Emma Thompson's comments likely to trigger a rush of steam from her ears.

The Oscar winner has spoken out against the use of sloppy language. She says people who speak improperly make her feel "insane" and she criticises teenagers for using words such as "like" and "innit".

But is peppering one's sentences with "like" such a heinous crime against the English tongue?

Language experts are more understanding of teen culture than Thompson, pointing out the word's many uses. It's the unconventional uses that are probably getting the actress hot under the collar. One of the most common is using "like" as a filler word in a conversation.

But fillers are a way we all stall for time when speaking and historically always have. It has nothing to do with sloppiness, says John Ayto, editor of the Oxford Dictionary of Modern Slang.

"It is not a lazy use of language, that is a common fallacy among non-linguists," he says. "We all use fillers because we can't keep up highly-monitored, highly-grammatical language all the time. We all have to pause and think.

"We have always used words to plug gaps or make sentences run smoothly. They probably did in Anglo Saxon times, it's nothing new."

But crucially, we often use non-word fillers, such at "um" and "ah". The fact that "like" is an actual word could be why Thompson doesn't like it.

Using 'um' may seem more correct to Emma Thompson because using 'like' as a filler is not a feature of her language Robert Groves, Editor of the Dictionary of the English Language Thompson attacks use of sloppy language

"When words break out from a specific use and become commonly used in a different way, people come down on them," says Dr Robert Groves, editor of the Collins Dictionary Of The English Language.

"Using 'um' may seem more correct to Emma Thompson because using 'like' as a filler is not a feature of the language she uses. The more disassociated you are from the group that uses a word in a different way, the more that use stands out. It will be invisible to teenagers."

Another common use of "like" by young people is as a quotative, which is a grammatical device to mark reported speech. For example: "She was like, 'you aren't using that word correctly' and I was like, 'yes I am'."

It is also commonly used to indicate a metaphor or exaggeration. "I, like, died of embarrassment when you told me to stop using slang." Alternatively, it is employed to introduce a facial expression, gesture or sound. A speaker may say "I was like..." and then hold their hands up, shrug or roll their eyes.

While certain uses of language - such as fillers - have probably always been around, the appropriation of "like" in this context can be traced to a familiar source of so much modern day slang- California's Valley Girls.

"Many of these uses of 'like' originate in America," says Dr Groves. "They were probably introduced into British English through the media, like films and television."

Using "like" in this way is also about signalling membership of a club, says English language specialist Professor Clive Upton, from the University of Leeds.

"If they [young people] do deploy the sort of language they're using on the streets in formal settings then it could well be a disadvantage to them but at other times it's quite clearly the way they get along, the way that they signal they belong in a group, the way that they fit in.

"And we all do that in our professional lives as well. We've got all our acronyms and our little words that we use that send a signal - I'm one of the club."

Thompson just isn't part of the "like" club.