Phonemic contrast of /i/ with /ɪ/ (beat vs bit vowels), of /u/ with /ʊ/ (fool vs full vowels), and of /ɛ/ with /æ/ (bet vs bat vowels) is rare outside northwestern Europe, so unusual mergers or exotic pronunciations such as [bet] for bit may arise. Note that [bɪt] is a pronunciation often used in England and Wales for bet, and also in some dialects of American English.
Native speakers of Arabic, Tagalog, Japanese, Korean, and important dialects of all current Iberian Romance languages (including about all of Spanish) have difficulty distinguishing [b] and [v], what is known as betacism.
Native speakers of almost all of Brazilian Portuguese, of some African Portuguese registers, of Portuguese-derived creole languages, some dialects of Swiss German, and several pontual processes in several Slavic languages, such as Bulgarian and Ukrainian, and many dialects of other languages, have instances of /l/ or /ɫ/ always becoming [w] at the end of a syllable in a given context, so that milk may be variously pronounced as [mɪu̯k], [mɪʊ̯k], or [mɪo̯k]. This is present in some English registers—known as l-vocalization—but may be shunned as substandard or bring confusion in others.
Turkish and Azeri speakers may have trouble distinguishing between /v/ and /w/ as both pronunciations are used interchangeably for the letter v in those languages.