One of the most common tasks in the ESL or EFL classroom in the use of pair work for English learning, especially when teaching conversational skills. The use of pair work is an important part of any classroom, but in English learning pair work is important for a number of reasons. Here's a short overview of how to use pair work in the classroom.

Pair Work Considerations

Pair work should be used as part of every lesson because it not only gives the students a chance to learn from each other, but it encourages the active use of English as students negotiate exercises together.

However, there are certainly a number of pitfalls when using pair work. If students don't get along, or one student is dominates the other, pair work can quickly become something students prefer not to do. This can lead to students wishing for a more teacher-centered lesson which in turns leads to a more passive learning approach. If the goal is to get students actively using the English language, then pair work offers one of the best tools. Here are some of the "DOs and DONTs" I've learned over the years. 

Pair Work DOs and DONTs

DOs

• Ask students to work pairs at least once every lesson. Even better, build pair work or small group work into every lesson activity.
• Pair students with speakers of other languages than their L1. This is not always possible, but pairing students who speak different languages forces English communication. Students who speak the same L1 are easily tempted to drop into their native language. 
• Switch pairs often, but not for every exercise. It's important to get the right balance here. If you switch too often, students who work well together feel robbed. Switching too seldom means students get frustrated with each other. I'd say once every two activities is a good balance. 

• Switch between pairing students at the same level and students at different levels. In some exercises, it's great to have the stronger students help weaker students, this is especially true in grammar activities. However, when it comes to conversational skills students at a similar level will feel more comfortable speaking with students at their level.
• Provide pair work tasks with clear objectives. Make sure that your activities or instructions clearly state how students should interact. Vague instructions such as "talk about your hobbies" can lead to discussion, but, especially in lower level classes, discussion and learning tend to need more structure. 
• Check on your pairs. You'll be able to spot trouble areas, provide needed input, and keep a tab on much more student progress than if you lead a classroom activity. 

DONTs

• If at all possible, don't pair up students who speak the same language. I know this is not always possible, but pair work between students who speak different languages is far superior as students have no temptation to drop into their native language. 
• Always pair students with the same partner. This trap is easy to fall into if students always take the same seats. Ask students to change seats often, and you'll avoid this pitfall. Some students want the same partner, but it's very important to make sure that students get used to having different partners. Each pair is a different combination and will call on different language skills as they negotiate their way through the exercises.
• Always pair students at the same level. Pair up different levels, but not too different. Stronger students can help weaker students, but be careful that this is what truly happens. Often stronger students take over the exchange as weaker students allow them to answer all the questions. 
• Stay out of it. In other words, DO move around the classroom and help pairs as they work on their activities DONT let students work it all out on their own.