"Please help my younger brother."
If it's not your family member then you cannot be so familiar to drop the 的. Just asked my wife, who teaches Chinese, and is a native speaker, and as long as it is your family you are talking about, you can drop the 的, but not someone else's family.
I don't think so... because some say 我弟弟 and some say 我的弟弟 its kind of the same meaning
Definitely should accept 我弟弟。The 的 particle is very rarely used with family members, especially when spoken.
well I studied Chinese at school and 帮 is like help, so you are right but 助 is usually used with 帮. hope I helped you :)
Bang is less formal and more likely ro be used in spoken situations, whereas bangzhu is more formal, like when asking a teacher to help your little broher.
Inconsistent use of zai in this sentence. The question before was translate the same sentence to English, but the Chinese had 再. When i used 再 it was counted wrong. You are training people incorectly.