The coach is trying to instill in/into the players a feeling of confidence.教练正试图使运动员逐步建立自信。Getting the certificate does a lot in terms of confidence building.获得这张证书在建立自信方面很有帮助。A course in assertiveness could help her overcome her shyness.修一门建立自信心的课能帮助她克服腼腆。