Drinking around an alcoholic, like it or not, puts up a "you drink, why can't I?" argument for the alcoholic--it does not matter if you can handle drinking because he or she cannot. It may also lead to unhealthy drinking habits within your own life. You can help the other person by meeting and spending time in places that do not serve alcohol. This will make it easier for the person to stop drinking. Ask people closest to the person if they've noticed any concerning behaviors or if they think the person has a problem. Avoid telling them the person is an alcoholic and be careful not to tell anyone who doesn't need to know. Don't risk destroying the person's privacy. If you think the person is an alcoholic, the time has come to get others involved. The problem is too big for you to tackle by yourself, and you must get outside help for the alcoholic as soon as possible. Remind him that you're worried, that you care about him, and want him to get help. Share your thoughts on what you've noticed and ask what you can do to help. Be prepared if the person doesn't want your help or avoids you for a while. If the person is open to getting help, offer to put him in touch with a professional. Have a list of resources ready to hand to the alcoholic. It should include contact information for local Alcoholics Anonymous groups, the names of therapists and psychologists who specialize in helping alcoholics, and a list of rehabilitation centers. If the alcoholic refuses to go into treatment or even consider it, try to involve a therapist. A therapist will have experience dealing with different types of alcoholics, and will work with you to create a plan for the alcoholic. A professional therapist will know how to handle defensiveness and other behaviors that may upset or confuse close family members. If the alcoholic does agree to go to treatment and take steps toward sobriety, make it clear that you're supportive and that this is the best thing the person could be doing. Curb the person's feelings of guilt or embarrassment...

TL;DR in Vietnamese:
Không uống rượu xung quanh đối phương. Nói chuyện với những người khác. Trò chuyện với đối phương. Cố gắng kết nối với chuyên gia. Luôn động viên trong suốt quá trình điều trị. Chuẩn bị để hỗ trợ cho sự tái phát. Quan tâm bản thân. Dành thời gian với bạn bè và thành viên gia đình.