就这两个句子而言，What's the size of your family 是正确的，意思是 “你家规模有多大的”。这是针对四世同堂的旧式家庭而言的，含有多少口人的意思。如果对现代家庭提问，最好用下面的句子：
How many people are there in your family?
How many persons are there in your family?
就这两个句子而言，What's the size of your family 是正确的，意思是 “你家规模有多大的”。这是针对四世同堂的旧式家庭而言的，含有多少口人的意思。如果对现代家庭提问，最好用下面的句子：
How many people are there in your family?
How many persons are there in your family?
