如果您的儿子英语考试没有考好，您可以这样表达："Unfortunately, my son didn't do well on his Engpsh exam." 或者 "I'm disappointed that my son's Engpsh exam results weren't as good as I had hoped."

建议您鼓励儿子努力学习，并且寻找帮助，比如增加英语阅读和写作的机会，或者寻找英语老师或辅导员的帮助。您也可以考虑让儿子加入英语俱乐部或者参加英语比赛，这样可以增加他对英语的兴趣，并且有机会和其他人一起学习和交流。