Define what type the following attributive clauses refer to.

1) I cannot find the letter which you gave me this morning. 2) Yesterday I spoke to a man, who had just returned from an Arctic expedition. 3) The clock which is handing in the hall is slow. 4) The magazine which you lent me is very interesting. 5) This is the book that you need. 6) My father, who was a sailor, often tells me stories about the sea. 7) Yesterday I met an old friend, whom I recognized at once. 8) The garden which is at the back of the house is very small. 9) A man who has no patience cannot play chess well. 10) My son has a German teacher, who knows German perfectly. 11) The street that leads to the theatre is very wide. 12) A man who looks after the books in a library is called a librarian. 13) Is that the man whom they are looking for? 14) The building which you can see over there is very old.