As part of my ESL lessons I try to encourage the students to not only complete their set tasks but also to have a 'chat' either before, after or while doing their work. While it seems like this is 'time wasting' for people who might be walking by our room, the students are getting such valuable experience in talking with an adult in English and also their peers.
During these conversations I try not to correct the students. Instead I try to model the correct usage of lanuage, allowing them to hear authentic English conversation, without putting pressure on them to perform in such a way. Over time the students begin to incorporate more authentic and correct uses of English language phrases into their own conversations.
I highly suggest - especially with new arrivals and those still developing English conversational skills (BICS) that you try to add some general conversations into your EAL/D groups.