Bütün- singular ( the whole) Tüm- plural (all) -Bütün karpuzu tek başına yedi. (He ate the whole watermelon by himself.) -Pazardaki tüm karpuzlar çürük. (All the watermelons in the bazaar are rotten.) However, we don't generally care about the difference and use them interchangeably. For example, there is a famous song "bütün kızlar toplandık"(we, the whole girls gathered) as if the girls who are gathered lack some part from their bodies. It should be "tüm kızlar toplandık" (we, all the girls gathered) But again, don't think about it. 1/100 person knows that rule in Turkey :D

Hi! The adjectives Tüm and bütün are pretty much the same. They basically have the meaning 'all', 'whole'. Additionally they can be used as nouns as well. Tüm/bütün gün evdeydim. (I was at home all the day) Tüm/bütün insanlar eşittir. (All humans are equal) As you see they have an identical meaning.