According to a couple of well-known online dictionaries [1, 2, 3, 4], Iran is most often pronounced in these two ways, in American English (AmE) as well as in British English (BrE):
If you follow this link to a dictionary entry above, you'll be able to hear the word pronounced by clicking on the little speaker icons ...
Use the "strong" version when speaking slowly, speaking for clarity, or when emphasising or contrasting the word you:
Use the weak version when the word is not stressed, when speaking quickly and when "you" is implied by the context.
I'm going shopping. You're going to do homework. No discussion! (/jɔːr/)
So, you're playing tennis tommorrow? (/jər/...
Bet-el-gurz.. No beat, no juice.
In Britain we still have a monthly astronomy programme called 'The Sky at Night'. It originated in the early 1950's and was introduced by Mr Patrick Moore. His pronunciation is reliable.
Not even a Cockney - Urban dictionary; Butcher's Hook & Wikipedia: Cockney - would turn that U into an A sound. It's a U & it sounds as a U.
British & US pronunciations, phonetic /ˈbʊtʃ.ər/ & sound bites are on - Cambridge Dictionary: Butcher
Even accounting for the vowel sound, it's one of those words where the T really is ...
There is no way to tell. You have to determine it from context (were we previously talking about one car or several cars?). If you are speaking and want to make it clear you could say something like "the tires of all the cars" or "the blue car's tires" (in the case where there's only one blue car we might be talking about) .
My favorite example is
An uninformed man
A uniformed man (a you-knee-formed man).
You use an if the next word sounds like it starts with a vowel, a if the next word sounds like it starts with a consonant.
There are cases where there is no universal agreement about pronunciation. Some people say "a hotel" (a hoe-tell), some say "an hotel" (an oh-tell). ...
The correct article to use is an undershirt
Google Ngram confirms
The American English term, undershirt, begins with a vowel sound
/ʌndərʃɜrt/ (Collins) and /ˈʌndəʃəːt/ (Lexico), and words beginning with a vowel sound take "an".
it was a hacker culture term years before gamers got hold of it. i heard it back in the late 80s / early 90s. pwn is a typo because on standard english keyboards the o and the p are right next to each other, the i is on the other side of o, not between them. i pwned that system... meaning you got an exploit that gave you total access to do what you wanted ...