I called the police but they weren't very helpful.
我叫了警察，但他們不太肯幫忙。
You'll find it helpful to talk things over with a friend.
把情況和朋友詳細聊一聊，你會覺得大有幫助。
The people I spoke to were very helpful.
我交談過的人都很肯幫忙。
It's natural to feel helpless against such abuse.
對這種虐待感到無能為力是自然的。
He lay helpless on the floor.
他無助地躺在地板上。
The audience was helpless with laughter.
觀眾情不自禁地大笑。