Identifying cognates is difficult because the languages in question are often separated by thousands of years of development and many languages within the family have long been in contact with each other, raising the possibility of loanwords.
aɪdˈɛntᵻfˌaɪɪŋ kˈɑːɡneɪts ɪz dˈɪfɪkəlt bɪkˈʌz ðə lˈæŋɡwɪdʒᵻz ɪn kwˈɛstʃən ɑːɹ ˈɔfən sˈɛpɚɹˌeɪɾᵻd baɪ θˈaʊzəndz ʌv jˈɪɹz ʌv dɪvˈɛləpmənt ænd mˈɛni lˈæŋɡwɪdʒᵻz wɪðˌɪn ðə fˈæmɪli hæv lˈɔŋ bˌɪn ɪn kˈɑːntækt wɪð ˈiːtʃ ˈʌðɚ, ɹˈeɪzɪŋ ðə pˌɑːsəbˈɪlᵻɾi ʌv lˈoʊnwɜːdz.