How is the nuance of each one?
- Do you need help?
- Do you need a help?
- Do you need any help?
- Do you need some help?
- May I help you?
And which one should I use to offer some strangers my help in stations etc.?
connotationsdeterminersword-choice
How is the nuance of each one?
- Do you need help?
- Do you need a help?
- Do you need any help?
- Do you need some help?
- May I help you?
And which one should I use to offer some strangers my help in stations etc.?
Best Answer
This is used for directly asking if a person needs help without thinking whether the person actually needs help or not.
This is not grammatical. "Help" is not a countable thing, so an article "a" shouldn't be used. (I learned this from @user3169)
This is used for offering help when an asker is not quite sure if a person being asked actually needs help.
This is used for offering help when an asker is pretty sure that a person being asked needs help.
This is kind of formal, something you would be asked by a staff at some store or by an operator of some company on the phone.
It's probably not a matter of one being better than the other. I'm sure native speakers are choosing which one to use intuitively (even though I'm not 100% confident in the definitions I gave you in my answer...)