帮【bāng】

帮 means "help". Followed by a person and a verb, it says you do something for that person or help them do it. The person goes right after 帮, and the verb after the person.

Often the helper does the whole job: 帮我买 is "buy it for me" rather than "help me buy it".

帮 or 帮忙

帮忙 is "help" with nothing after it. It already contains its object (忙, "a favour"), so it can't take a person. The person either goes with 帮 alone or sits inside: 帮我一个忙.

• × 你能帮忙我吗 → 你能帮我吗
• × 他帮忙我搬家 → 他帮我搬家

帮助

帮助 is the fuller form of "help", more formal, and it is also the noun.