I have had a number of students who seem to be intimidated or shy and do not ask questions either during class participation or even one on one with me. They seem to be struggling but when help is offered or when I try to find out why they are struggling, i get nothing out of them. They almost seem as if they are not interested in learning or really have no desire or motivation. Other than letting these students fall behind, what other techniques could I try to get them more motivated to ask questions or even go to someone for help of they are not understanding the material?