Anyone, any one :
Anyone is singular and normally takes a singular verb and is referred to by a singular pronoun or possessive adjective : Has anyone a pen he can lend me ?- not they.
Anyone who wants to enter the competition may send his name - not their.
But, when anyone is used in a general, and not an individual or specific sense, so that it has the force of all, without exception, a plural is allowable, since the singular would sound incongruous : Anyone can enter the competition, can't they ?'- Wood.
Anyone is a compound and refers to persons only.
But, when the reference is to things or "one' has a numerical sense, any one (two separate words) must be used : Which dress would suit you ? - Any one would do. Any one of you will be suitable for the job.
Any, Some :
(a) As Adjectives of Quantity or Number :
(i) Any is used in negative sentences ; but some, in affirmative sentences:
He did not want any man.
I do not see any birds on the tree.
He gave me some books.
Please give me some milk.
(ii) In Interrogative sentences, both are allowable ; but any is to be preferred :
Is there any man there ?
Has he any letters for me ?
But some is rightly used in questions which are really commands or requests :
Will you give me some water ? (= Please give me some water)
(b) As Demonstrative Adjectives, both may be used before either number in affirmative as well as negative sentences; but any is more indefinite than some :
Any road will lead you there.
Any book will do to while away the time.
He did not go to any friend.
You may have any books you like.
Some men are healthy.
Some boys must have done this.
