英语作文建议信的开头、中间和结尾可以这样写：
开头
开头句：首先表达你了解到对方在某个问题上的困难，并表示愿意提供帮助。例如：“I have learned that you are facing some challenges with English learning and would like to offer you some suggestions.”（我知道你在学习英语方面遇到了一些困难，因此我想给你提供一些建议。）
自我介绍：简短地介绍自己，说明写信的目的。例如：“I am [Your Name], a fellow student who has also faced similar challenges and found some effective strategies that might help you.”（我是[你的名字]，一个也遇到过类似挑战并且找到了一些有效策略的同学，希望这些策略能对你有所帮助。）
中间
分点建议：将建议分成几点，逐一列出。例如：
“Firstly, I suggest you to practice listening to English every day. This can be done by listening to English songs, podcasts, or watching English movies.”（首先，我建议你每天练习听英语。可以通过听英语歌曲、播客或观看英语电影来实现。）
“Secondly, it is important to build a strong vocabulary. Try to learn new words and phrases daily and use them in sentences to better remember them.”（其次，建立强大的词汇量很重要。每天尝试学习新单词和短语，并在句子中使用它们以更好地记住它们。）
“Lastly, don't be afraid to make mistakes. Making mistakes is a natural part of the learning process, and the more you practice, the better you will get.”（最后，不要害怕犯错误。犯错误是学习过程中的自然现象，你练习得越多，就会变得越好。）
结尾
总结：简要总结你的建议，并表达希望对方能够采纳这些建议。例如：“In conclusion, by following these suggestions, I believe you will see significant improvement in your English learning.”（总之，通过遵循这些建议，我相信你会在英语学习上取得显著的进步。）
期待回复：表示期待对方的回复，并表示如果需要进一步的帮助，愿意随时提供。例如：“I hope you will find these suggestions helpful and that you will consider implementing them in your study routine. If you have any further questions or need additional assistance, please do not hesitate to reach out.”（我希望这些建议对你有所帮助，并希望你能考虑将它们纳入你的学习计划。）
通过这样的结构，你的建议信会显得清晰、有条理，并且能够有效地传达你的想法和帮助。