1.经典句型：I'd like to ask you for help. 我想请您帮忙。
A: I'd like to ask you for help.
B: I'm glad to help you.What's the matter?
A: Would you please look after my pet dog?
B: No problem.Where are you going this time?
A: I'm going to Beijing to attend a conference.
2.经典句型：You are always so accommodating. 你总是那么乐于助人。
A: I'd like to take care of your dog.
B: Thank you. You are always so accommodating.
A: It's my pleasure.
请求别人的帮助时，可以说We have to ask you for help. 我想请你帮个忙。希望帮助对方，则可以说I'mvery glad to help you. 我很乐意帮助你。