For example, why do you think people might have a hard time learning a new language? An example could be that the person is in shock due to a new culture, country, etc. This can prevent them from learning a language. Some people are forced to leave their country and might not want to let go of their own languages and ways. Disabled students might have a hard time learning a language. For example, if the class is shown a family tree and the teacher is identifying family members, this would be very difficult for a blind student to understand. I will keep thinking, but at least you have some ideas.......... bonne chance!