Paintwork is used to give students the opportunity to communicate in English with another individual who is not the teacher. As, in classes larger than about four people, it is utterly impractical for the teacher to attempt to talk to each member of the class, having the students talk to each other is seen to be the solution. The arguments for and against the practice are outlined below.
 Why pairwork?
Pairwork is deemed necessary for a number of reasons:
- It is not possible for the teacher to practice individually with students in a large class.
- Having the students talk to each other without the whole class listening to them lowers the affective filter.
- When the students talk to each other they are able to notice errors made by their partner and eliminate them from their own speech.
- The weaker partner in the pair is given a good model to follow.
 Objections to pairwork
Pairwork is not universally popular and the following criticisms may be heard:
- It is a second best solution to the problem of teachers having classes so large that they cannot deal with students individually. It is a case of making a virtue out of necessity.
- Teachers are not able to monitor every conversation.
- Students in monolingual classes may speak in their L1.
- Rather than learn from each other, students may simply re-enforce their mutual errors.
- Whereas the weaker member of the pair may have some advantage, the stronger member is simply an unpaid teacher.
- Some students think the activity is pointless.
Nevertheless, a good teacher should be able to overcome some of these issues.