How to use "helpful" in a sentence

Officer Ekker was very helpful

So I empty my pockets, and at first there is nothing helpful there: no wallet, no keys and no phone

"Just trying to be helpful, love

They have told me since that I was singing a crazy song about 'The Last Man Left Alive! The Last Man Left Alive!' Although they were troubled with their own affairs, these people were very helpful to me

Perhaps this attack from Mars will be helpful to us in the end

Then he said, 'You've been very helpful to me, so now I'll help you