写作思路：
首先开门见山地感谢朋友的邀请，然后表达一下自己对朋友之间的友谊的看法。
篇一：
Dear xxx:
It is so nice of you to invite me to your house.I think it will be a precious chance for me to know your family.You see,we get along well with each other and learn from each other.I really enjoy the friendship between us.
Your encouragement,your generosity and your frankness have left me deep impression and given me very good influence.And my mother used to tell me that I had had a graet change since I knew you.
Anyway,I am really appreciate to your invitation and I am looking forward to being with you and your family.
Yours,XXX
译文：
尊敬的xxx：
邀请您到我家来，真是太好了。我认为这是我认识你家人的难得机会。你知道，我们彼此相处融洽，彼此学习。我非常享受彼此之间的友谊。
你的鼓励，你的慷慨和坦率给我留下了深刻的印象，并给了我很好的影响。我的母亲过去常常告诉我，自从我认识你以来，我有了一个彻底的改变。
无论如何，我真的很感谢您的邀请，并期待与你和你的家人在一起。
你的XXX
篇二：
Dear friend:
Thank you for inviting me to your home for dinner. I am very happy tonight. I think you have a good meal. If you are free, the next time you can come to our house, I will make a big dinner for you. Look forward to your visit.
Yours,XXX
译文：
亲爱的朋友：
谢谢你邀请我去你家吃晚饭。 今晚我很开心。 我想你吃一顿饭。 如果你有时间，下次你可以来我们家的时候，我会为你做一顿丰盛的晚餐。 期待你的光临。
你的XXX