I learned English as a teenager and am now teaching it to school aged children and adults. I think building vocabulary is essential when teaching English Language Learners conversational/essential English. Using "realia" (real objects things they can see or touch) when introducing new vocabulary is of great help, it gives them a very real reference point that does not require translation into their primary language, therefore a connection is created without relying on translation as a means of learning a new language. I also find that chants or songs are effective ways of teaching pronunciation or phrases that are part of everyday life. You can accompany this with actions/movement/pictures therefore increasing the number of connections the child(ren) makes and using as many learning modalities as possible. I know this has worked for me and my students so I hope it works for you and your students as well.
