During the last five minutes of your lesson, give your students an outline of everything that you expected them to get from your lesson. Go over the outline with the students and ask them if there are any questions they may have. Be patient. Sometimes the students are unresponsive, but if you ignore the awkward silence for a minute or two, they may speak up after a while. Alternatively, pass out pieces of paper on which they can write a question they may have. Collect the questions (but let them keep the outline) and tell the students that you will address the questions when you return next week.