What’s the first thing that comes into your mind when you see these expressions?
Your answer is probably that they are all idioms: groups of words that not only have a meaning that is different from the individual words, but also a meaning that is often difficult or impossible to guess from the individual words. If someone is barking up the wrong tree, they have the wrong idea about how to get or achieve something; it has nothing to do with – or is unlikely to have anything to do with – dogs or trees. If you have egg on your face, you might need a handkerchief, but it’s more likely that you are embarrassed or feel stupid because something you have tried to do has gone wrong. These expressions are also good examples of the commonly-held view that idioms tend to be very vivid and colourful expressions.
Now, let’s turn to another list of expressions. What do they have in common with the list above?
Less obvious perhaps, but the answer, in fact, is the same: they are all idioms. Is the meaning of these expressions very different from the individual words? Not to any great extent. Is the meaning difficult or impossible to guess? Not particularly. Are they vivid and colourful expressions? Certainly not. So, why are they idioms?
The common factor with both of the above lists is that the form of the expressions have become fixed, or frozen. You can have a storm in a teacup but not a storm in a coffee cup; you can say I’ve no idea, but not usually I don’t have an idea (though you can say I don’t have the faintest idea).
Do all idioms have a fixed form like this? No, they don’t. With some idioms, certain words can be replaced by other words:
In other cases, a different word can be substituted which changes the meaning:
With such range and diversity, it’s probably worth checking if something is listed as an idiom in the dictionary. If you do though, you will find that even dictionaries do not always agree. Cross your legs is given as an idiom or fixed expression in the Macmillan English Dictionary, but in the Longman Dictionary of Contemporary English it is listed as one particular meaning of ‘cross’. Take offence is shown as an idiom or fixed expression in Macmillan, but a collocation in the Oxford Advanced Learner’s Dictionary; be to blame for sth, however, is an idiom in Oxford, but a collocation in Macmillan; and so on.
Clearly, idioms are not a water-tight category. There are degrees of idiomaticity, and the dividing line between, for example, idiom and collocation can be a fine one. It also seems that idioms include a greater range of expressions than some may have previously thought. At one end of the spectrum are the more opaque and picturesque examples such as pull the wool over someone’s eyes; at the other end are the more mundane and transparent examples such as if you like or the night before last. Given this range, do they deserve more attention in the teaching syllabus than we have previously given them?