请问When will it be convenient for you?句中在“convenient”人何要加“be

请问When will it be convenient for you?句中在“convenient”人何要加“be When will it be convenient for you to come? Will it be convenient for you to start work tomorrow? "when will be convenient for you to come?"中空处填it还是there 时间状语不用介词When will it be convenient for you?Anytime on next M it is convenient for you to do 这里for you在句中是什么结构 convenient词组be convenient for sb.to do sth.,为什么到句子“If it is Can you suggest a time()it will be convenient to meet? Can you suggest a time____it will be convenient to meet? When is it convenient for you?(中文标着念） 英语翻译would it be convenient for you to pick me up at four o'c be convenient to