We Have to Talk
There's a pervasive communication problem in the English language that I feel it important to address.
Needs are things like oxygen, hydration, food, sleep, shelter — things that a person or other living being must have in order to live, or things that a machine depends on in order to do its function.
Doing a chore, running an errand, filling out a form, signing a document, turning in an assignment, making a payment, and other things of that nature, are obligations, not needs. There's a difference.
Telling someone that they need to do something is to tell them harm will come to them if they don't. If it's a mere obligation, then saying they "need to" is unnecessarily rude, harsh, forceful, angry, condescending, threatening, and, unless they've really really wronged you, uncalled for. Saying it to someone at work is unreasonable. Saying it to a child is unconscionable.
Saying "I need you to..." is not much better because now you're accusing the person of harming you.
Most languages do not do this. It really breaks my heart that English has come to this. I'm trying to be reasonable here, but every time I hear someone make this grievous error, especially if they're smiling, it leaves such a bad impression.
References:
Slate.com - How Need to Vanquished Have to, Must, and Should (archived)
Word Hero - Kindergarten Imperative (archived)