我家有四口人，爸爸和妈妈，姐姐和我。我的家庭很幸福。
英文翻译：
There are four people in my family, my father and mother, my sister and I. My family is very happy.
语法分析：
my father and mother, my sister and I
作four people的同位语，对其进行解释或补充说明。
重点词汇解释：
family
|ˈfæməli|
(pl. -ies)
[可数名词+单数/复数 动词] a group consisting of one or two parents and their children 家，家庭（包括父母子女）
happy
|ˈhæpi|
(happier, happiest)
giving or causing pleasure 给予（或带来）快乐的；使人高兴的；幸福的
