form (am) for first person and singular number. whose indicates that the antecedent has a possessive role in the relative clause ("The man whose daughter I married"). Unlike who, it can refer to things as well as persons ("I found a car whose battery was dead"). Though there is some reluctance to use whose with a non-personal antecedent, such use is not uncommon and is perfectly grammatical. Whose is used in both restrictive and non-restrictive clauses (“The woman whose brother was recently married ...”, or "Sally, whose brother ...") and with both fronted and stranded prepositions ("The student in whose car we arrived ...", "The student whose car we arrived in ...") or larger phrases with a preposition ("My tutor, some of whose lessons..."). A relative clause whose antecedent is a whole propositionthat is, a matter (or person or thing) to be dealt withis formed with which ("The cake was burnt, which made me angry"); here which refers to the whole circumstance of the cake's being burnt. A formal, though uncommon, use of which is its being a relative determiner in non-restrictive clauses ("He painted a picture of the house, which painting I later destroyed"). Here, which may refer to persons as well as things (“Yesterday, I met three men with long beards, which men I remember vividly”). Which can also refer to the whole clause, followed by a word that represents the ideas of the clause ("Yesterday, I met three men with long beards, which meetings I remember vividly"). A preposition may be fronted in front of the relative determiner which ("Every day, he visits me at the arcade, from which fact I derive much pleasure"), as may a larger phrase containing a preposition ("He went to the park and the shopping center, both of which places ..."). A free relative clause has no antecedent and takes the role of an argument in the main clause. When referring to people, it is formed with the pronouns who, whom or whoever, whomever ("I'll take who you choose", or "I'll take whom you choose", or "I'll take whoever (or whomever) you choose"). When referring to things, it is formed with the pronouns what or whatever ("What I said annoyed her") where what stands for "the thing which ..." or "that which ...". Whichever is used when referring to people or things from a known set. (These are all called compound relative