How would you spell "Tehran" in English for it to be pronounced "correctly" (i.e. as in Persian)?

Native English speakers do not pronounce the h in Tehran so it is pronounced like "Teran". But in the original pronunciation in Persian the h is pronounced, resulting in /tehˈɾɒːn/.

Is there any alternative for the spelling of Tehran to be pronounced "correctly", i.e. as in Persian, by a native English speaker?

(I'm asking this question because a friend is asking me for the correct spelling of his name Mehran which with the exception of the first consonant is pronounced like Tehran.)

Edit: Bahrain (البحرین) is another similar word with the h dropped in its English pronunciation /bɑːˈreɪn/, while in Arabic it is /bɑːħreɪn/.

Solution 1:

There is no way to truly force this pronunciation in English.

In English, we just don't pronounce the /h/ sound at the end of syllables. Because it is not a part of our phonological grammar, it can be difficult for a native English speaker to articulate the sound, or even perceive the sound at all, in that context. So, even if you pronounced it correctly and asked the native English speaker to repeat after you, they might still leave out the /h/ sound.

Since there is no context in which an English speaker pronounces /h/ at the end of a syllable, there is no spelling convention that indicates it should be done to someone who is unfamiliar with Farsi.

It is similar to trying to write something in katakana that will make a native Japanese speaker pronounce "cat" as we do in English. Japanese speakers have the /t/ sound, but it can't occur at the end of a syllable, so the closest approximation would be "kato" (or "katto" but let's keep it simple).

There are two spellings available to you, each one sacrificing one feature in favor of another.

1. The standard spelling "Tehran" maintains the two-syllable prosodic form and indicates the "h" for those who are familiar with Farsi Latinization and phonology. But it will not cause an average speaker to pronounce the "h".
2. The alternate spelling of "Teheran" (which was mentioned in the comments) puts the "h" in a context where it can be pronounced (at the beginning of a syllable — "he"), but in order to do so, adds a vowel and therefore another syllable. This is called epenthesis and is also how Japanese (among many others) repair unpronounceable clusters. The disadvantage is that you now have three syllables instead of two; also, you still aren't guaranteed to get pronunciation of the /h/ sound — between vowels, an "h" in an unstressed syllable often goes unpronounced in English.

Solution 2:

I guess you could go with Té-hraan, even though looks like something out of a sci-fi novel. The acute accent over the E forces it to be pronounced more like [ e ] (usually [ ɛi ], diphthongised), and doubling the A gets you closer to [ ɒː ] rather than [ æ ], but it's still tenuous. Téhraan (without the hyphen) probably wouldn't work, because H-dropping takes precedence, and accents tend to be ignored unless their effect is quite pronounced. (Pun intended.)

Solution 3:

The premise of the question is probably false.

Tehran is spelled Tehran (or Teheran) in English.

You may attempt to spell it, using the letters commonly used in English, in such a way as to encourage English speakers to pronounce it as its Persian name is pronounced by Persian speakers. But then you are not spelling it in English. I would try Teh-ran but I think any such attempt is unlikely to succeed to any significant degree.

The most accurate way to spell it would be in IPA — but few English speakers know IPA.

Solution 4:

All languages have a repertoire of phonemes (except in some modern linguistic theories which I'm ignoring for this answer). Each language also has phonological rules which define things such as which combinations of phonemes are acceptable, or in which positions in a word or syllable a phoneme can be. For instance English doesn't like more than a few specific combinations of consonants without an intervening vowel and Spanish doesn't like words beginning 's' following by another consonant unless preceeded by 'e'.

On top of that each language has its own orthography which maps letters and other symbols to sounds. These are seldom perfect. English orthography is notoriously irregular. Persian orthography is ambiguous in that most vowels are not written.

On top of that there may be multiple varieties of a language who would not pronounce a word the same even when they write it the same, and even moreso for foreign words which might push the limits of orthography as used in native words. English has two major such varieties, British and American. (and many other varieties)

Give all this it's rare that a Persian word will sound the same when spoken by English speakers and equally rare that an English words will sound the same when spoken by Persian speakers.

The best we can do is map each phoneme from the source language (Persian) to its closest in the destination language (English), keeping in mind that the available phonemes vary. Then we have to choose a spelling to map English letters to those phonemes, not always easy given English spelling. But even if we do this very well and close phonemes are available we can still end up with a word where a perfectly good phoneme is in a position English doesn't like. And this is what happens with the "h" in "Tehran". English speakers are capable of pronouncing it but it "feels wrong" so many speakers will omit it.

Solution 5:

There is no good, unambiguous way of indicating that a "h" should be pronounced.

In other contexts, certain dialects (notably Scottish) might use "ch" (as in "loch"). It's unlikely to help in your case, because "tech" and "mech" are already words with defined sounds.

Probably the best you can do is to use punctuation to indicate a glottal stop.