For example, in Persian Farsi and Arabic these the the long 'i' sound which occurs when a Yeh comes after a Kasreh and doesn't have a vowel itself, i.e. ـِي and sounds like the 'i' in 'machine'. In Afghan Farsi though, as well as older Farsi, there is a long 'e' sound, which sounds like the 'ee' in the word 'eel'. So for example, instead of 'Iran' in Persian Farsi, some Afghans pronounce it as 'Eran'.
Most Persian dialects in Afghanistan (except in the West of the country, e.g. Herat), and also formal Persian as spoken by educated Afghans, distinguish clearly between historic /ī/ and historic /ē/. Afghans are very disapproving of the fact that Persians do not (supposedly) know the difference between “milk” (šīr) and “lion” (šēr).