to dear English teacher
just “happy birthday to you”,l know this gift is nothing ,Although there is no beautiful flowers ,but this is my heart
l wish you a perpetual youth!

敬爱的英语老师
仅仅一句生日快乐，我知道这点礼物算不了什么，虽然没有美丽的鲜花，但是这也是我的一番心意。
祝你青春永驻！

你犯了一个大错误哟亲！有although 在你就不能用but!

送给英语老师。怕语法出错，求大神纠正

目测楼主初中。although不能与but连用。

there are no beautiful flowers,flower你用了复数哟

亲爱的英语老师：my dear English teacher.

恩．．．个人认为你用just a word that happy birthday to you is noting更好一点

- - 我觉得最后一句怪怪的。。。 不用I好吧。。。。。 好吧，，我乱说的

this is gift without beautiful flowers,but my best wish in card

Dear English teacher
Lhappy birthday to you, a little cannot stands for all love and thanks to you , Flowers are beautiful ,and you are more beautiful than them in our eyes.
best wishes.

刚才我注意到最后一句，为什么不写I wish you have a perpetual youth 或者I wish your youth is perpetual 我愿你青春永恒

好像没有注意到标点符号。个人觉得，这也是我的一番心意。
翻译成：this is my heart有点中式英语了。

LZ写的是中式英语
Mrs.XXX
Happy Birthday！ Thank you for everything you have done for us and I cannot imagin what my school life could be without you. It's a shame not having been able to present you a gift or something， but I believe that it is my sincerity that matters most. Anyway，Happy Birthday！
Frankly Yours
XXX