They can, but not with exactly the same meaning. Have you looked up the words in a dictionary?
Let's suppose that someone saw very unusual design of building or clothes or style. And he or she was deeply touched by that unusual design, than the person might want to say something about their thought or feeling. In this situation, which word is suit for the situation between "distinctive" and "unique" in spoken English? Can "distinctive" and "unique" be both used in this light?
NOT A TEACHER
Distinctive means "having a special quality, character, or appearance that is different and easy to recognize", and "unique" means "unusually good and special", so in essence, only a very special building can be called "unique", while a moderately special building is "distinctive".
Source: Longman Dictionary of Contemporary English
Last edited by Chicken Sandwich; 18-Jun-2012 at 00:26.