Question is what is difference between these three questions. Edited Would you take care of your brother? This is a question of intention or desire. i would change it to: Would you take care of your brother if he needed your help. Will you take care of your brother? This means the need is already present. Will you take care of him now! Do you take care of your brother? This is a current question. Do you take care of him presently. Dr Daryl

The frist two are different tenses, Would is different from will, will is the future, while Would falls into the conditional. Do you care take of your brother. The English is wrong and I'd have to change a bit to make it right, let's try Do you take care of your brother? Is present, are you actually caring for your brother at present.