My personal theory is that this is because you can make every sound you hear in English using the Devnagari script, but not the other way around.
This is not very close to true. English (even a given accent) has a rather high number of phonemes, and they don’t overlap very closely with Hindi. What is probably more relevant here is that Devanagari is relatively phonetic so writing in it is useful to describe English pronunciations, more so than the English script is for Hindi (or English, for most unfamiliar words).
A very incomplete list of languages by approximate number of phonemes: https://en.wikipedia.org/wiki/List_of_languages_by_number_of...
It's true that the English language has a very large number of phonemes... but accents tend to regularize/restrict these phonemes. For example, a typical bilingual speaker of Indian English and Hindi will replace instances of the /æ/ phoneme (as in "blast" or "fast") with another phoneme like /a:/ (as in "father"). Which isn't that unusual since /æ/ is pretty uncommon among languages.
Other rare English phonemes include the dental fricatives, i.e. the "th" sounds in "ether" (voiceless) and "either" (voiced). Speakers of Indian English often replace this with a dental stop, a "t" sound (voiceless) or "d" sound (voiced). (Note that Devanagari has a _lot_ of stops, so this is one place where it cannot be cleanly encoded into the Latin alphabet without diacritics.)
So overall: while I think Devanagari can't encode e.g. American English, it can actually do a pretty solid job of encoding Indian English, but not the other way around.
> For example, a typical bilingual speaker of Indian English and Hindi will replace instances of the /æ/ phoneme (as in "blast" or "fast") with another phoneme like /a:/ (as in "father"). Which isn't that unusual since /æ/ is pretty uncommon among languages.
does not apply to Indian languages because most of them have daily-use-words with the /æ/ sound.
Not true. There are phonemes which are similar but distinct.
For example
- `v and w` map to the same thing in Hindi
- th and थ are allophones but different sounds
Hindi written in Devanagari is highly phonetic (not perfect but near perfect). However, English is not phonetic at all. E.g., "Th" in Then is different from the "Th" sound in Father.
In US pronunciation, Then is ðɛn and Father is ˈfɑðɚ.
In UK (received), Then is ðɛn and Father is ˈfɑːðə(ɹ).
In Indian English, Then is ðɛn and Father is ˈfɑːd̪ə(r)
The English Latin letter arrangement holds a tenuous phonetic connection to pronunciation half the time, whereas the devanagari usually indicates exactly how you say it.
As a Bollywood superstar famously quotes: English is a funny language.
As a Britisher learner it's frustrating¹ actually, because there is a standard for how to do this - IAST, for Sanskrit/derived generally - but of course that's not what native speakers use casually. E.g. your 'angrezi se hindi' would be 'añgrezī se hiñdī' but anyone writing Hindi with those accents is foreign or an academic. (Also people will casually write 'ay' instead of 'e' ए or 'ee' for 'ī' ई, etc. cf. 'paneer'.)
[1: The frustration is because it leads to ambiguity, whereas IAST is 1:1 and so preserves the phonetic nature of devanāgarī, and tells me exactly which t/d/r sound, if it's aspirated, etc. which a fluent native layperson's anglicised interpretation really doesn't. They might write gora & gora and know from context if that's gora or ghoṛā, but if I don't already know the word a gora like me is stuck.]
I learnt about IAST only after seeing how foreigners transcribe Sanskrit texts in Latin.
See this amazing article by a Polish journalist https://thediplomat.com/2021/01/spell-it-out-should-english-...
That should be 'aṅgrezī se hiṅdī' per IAST. In Devanagari: अंग्रेज़ी से हिंदी
If it were ñ instead of ṅ, the Devanagari would be अँग्रेज़ी से हिँदी which is incorrect.
(I also am often unsure which is correct, since as you no doubt know it's so common to drop the चंद्र and write हूं for example where it's properly हूँ )