Translation:These are the cats whose color is brown.
I understand the structure of this sentence (which is the important part since this is the relative pronoun lesson ), but I am just wondering if this is commonly said this way in Greek? I ask because the English equivalent sounds a bit strange- without further context it implies that there are several groups of cats that have different colors (i.e. NOT cats with fur of certain colors, but cats that have colors in their possession- like on pieces of paper). and one is specifying the group of cats that have brown. To imply that the cats have brown fur one would simply say "These are the cats that are brown." Στα Ελληνικἀ that would just be "Αυτές είναι οι γάτες οι ποιοι είναι καφέ" right?
Whoops, I made a mistake there with the gender of the pronoun, αλλά τώρα καταλαβαίνω, ευχαριστώ! (All the same though, the English translation for this sentence sounds a bit odd...I suppose it is because the pronoun "whose" (in English, at least) usually only takes a human antecedent, so since the antecedent in this sentence is "cats" it sounds funny- as if the cats are being personified...if the sentence had been something like "These are the men whose hair is brown" it sounds much more natural.)
Whose is the possessive form of both who and which.
Is it more common in Greek to personify?
No, in fact I'd argue the opposite is true as we use he/she/it for an(y) animal in Greek, depending on what grammatical gender the word describing it is, but in English people will use specifically he or she when talking about a specific animal, especially for pets.