New teachers are particularly challenged by the "what", "why", "how" and "when" of error correction because effective correction of errors draws together a number of skills all at once. You need to be a linguist to recognise the language problem and to understand why a learner with a particular language background may have difficulty. You need a selection of techniques at hand to help you decide "how" you are going to correct in a certain situation. And finally, you need the empathy of a counsellor to recognise the best time to apply the remedy.

First of all, what do we correct? If a student makes an error our first reaction is that something doesn't sound right. Such errors often fall into the category of a "slip" or moment when the learner has made a mistake, not because of any lack of knowledge but simply because of a momentary lapse of concentration - a linguistic banana skin. However, more complex errors fall into categories; for example, is it a problem of vocabulary or grammar? In these cases you'll need to draw attention to the reason(s) for the error.

Knowing why an error occurs will also help you to decide whether to correct it all. For example, it may be inappropriate to correct a language point that has no connection with the aim of your lesson and it would be totally ingenuous to correct something that has not yet been taught.

If the depth of knowledge required for this kind of instant analysis is daunting, you can help yourself by predicting the errors you might expect in a lesson. Any new language point will generate errors - errors are a sign of learning - so the clearer your aims the easier it should be to predict the errors.

Once you've decided what the error is and why it's happened you're in a position to decide "how" you're going to respond. At its basic level error correction is the teacher stopping the student and pointing out a problem. Drawing attention to an error can be done in all sorts of ways: a raised eyebrow, a lifted pen, the error repeated with rising intonation or a finger pointed to the correct form in a book or on the board. How we correct will depend on the seriousness of the error and whether we think it can be dealt with quickly.

Many teachers encourage students to correct each other. This works well in pair or group work. It encourages team spirit and has the benefit of reinforcing the language in the other students' own minds as well. There is a danger that a student may be getting incorrect information from a peer, but careful monitoring on your part can resolve this.

Finally, deciding "when" to correct in a lesson will depend on how much teaching time you can spare. Very complex errors might even be put to one side to be formally taught as part of another lesson. With written errors it's often the case that these are spotted at the marking stage. Spoken errors, on the other hand, can be corrected on the spot. In a fluency activity such as a role play you won't want to spoil the flow so note down common errors that you hear and write them up on the board. At the end talk through the errors either explaining the problem or eliciting suggestions from the class.

In some instances - especially one-to-one teaching - a student will ask you to correct all his or her mistakes. This "fire-fighting" approach has the demotivating effect of ignoring the need for developing communication skills and fluency. One solution is to record parts of the conversation to allow fluency and then promise the student that the recording can be played back later to analyse errors together.

"How" and "when" to deal with errors will also be controlled by the lesson's cultural context (for example, the culture of the country you are in) and classroom constraints (from five students in a circle to 50 students in rows) and so your approach to error may be tempered by your students' expectations. An unwillingness to correct regularly and instantly may be interpreted as the teacher not doing his or her job properly.

The one thing you can be sure of in any part of the world is that, while views on approaches to error correction may vary, the need to balance mistake-spotting with words and phrases like "Well done, Great, That's really good, You did very well", is universally popular. Always remember that complementing students on successes and positive reinforcement of what they do well should be very much part and parcel of any approach to error correction. It may even have greater benefits than the tireless pursuit of what went wrong.

The Guardian