How i can make old people understand and learn english language?

I teach English to adult language learners. It is definitely more difficult to start learning a language as an adult than as a small child, but it is not at all impossible. For adults to be motivated to learn English (or any new language), they need to feel that it is useful to them. From the beginning, teach them words and phrases that they can put to use immediately. Tailor your lessons to focus on their needs. Are they working in a company where the language used for business is English? Teach them phrases they will hear or need to use in the office setting. Are these elderly people who live with their adult children in an English speaking country, and they just need to know how to navigate local life? Start off by teaching them language they can use to introduce themselves to people at parties or to do their grocery shopping. The important thing is to make it relevant. If it is useful for them, they will enjoy learning it.