About 50% of Indians use Hindi as their primary language. Hindi/Devanagari is fairly phonetic except when it starts to import foreign words. And that’s why many Indians, with Hindi as their primary language, end up with incorrect pronunciations of foreign, mainly English, words. Let’s look at a few specific categories of mistakes.

Approximating English sounds to the closest Hindi sounds

During the medieval period, when Persian/Farsi words were being imported into India, nuqta ( नुक़्ता) was added to map new sounds, the common ones being ज़ and फ़ and the less common ones क़, ग़, ख़. Without these sounds, especially, ज़ and फ़, the pronunciations would have been noticeably incorrect. The same approximation mistake is happening with English sounds now.

1. English does not use bi-labial फ, it uses the labio-dental फ़. The bi-labial फ is made by bringing the lips together while the labio-dental फ़ is pronounced by touching the upper lips with lower teeth. So saying फोन, फिल्म, or फर्स्ट is incorrect. The correct words are almost always with फ़, that is, फ़ोन, फ़िल्म, and फ़र्स्ट. Surprisingly, फ़ which was first introduced for Persian/Farsi words has mostly disappeared from the lexicon, or at least from most Hindi newspapers.
2. Another labio-dental sound missing from Hindi is “v” (see v vs w). Many languages, like Hindi and Spanish, do not have the labio-dental “v” sound. So, a Hindi speaker doesn’t distinguish between the pronunciation of “vet” and “wet”.
3. A more subtle mistake happens with retroflex/ मूर्धन्य sounds that involve curling the tongue and touching the ceiling of the mouth. Sounds like ट, ड, ण, ड़, and ढ़ are retroflexes. Out of these, ट and ड are deceivingly closer to the English sounds of t and d. The English equivalents, however, do not involve retroflex at all. The t, as well as the d sound, is made similar to how one would make the L/ल sound.
4. English has two sounds for “L”, the light “L” is the same as Hindi “ल” but there is a dark sound for it as well. What’s worse is that these sounds have the same IPA symbol. For example, “Love” has a light L while the word “real” has a dark L sound. So, how should we map it? Again, nuqta for rescue. A new symbol “ल” with nuqta can map to this sound.
5. The English letter “R” is pronounced in the middle of the mouth by flexing the tongue backward. Hindi " र" is pronounced in the front of the mouth, so, the sounds are subtly different. Better to map English R to the letter ऱ that’s currently not used by Hindi.
6. The English “B” sounds very similar to Hindi ब. And they are indeed pronounced the same way but the English one is plosive while the Hindi ब like Spanish B is much softer in nature. If you put your hand in front of your mouth and say “B”, you can feel the explosive gush of the air, not so much with the Hindi ब.

Transliterating English spelling and not pronunciation

This is an easily fixable mistake but still, a lot of textbooks and newspapers do this.

1. " accessories" gets transliterated as एक्सेसरीज (about 2 million search results) and not एक्सेसरीज़ (about 1 million search results). The same goes for other imported words like Easy, as in the name of the Indian chain store EasyDay, which newspapers translating the spelling write as ईजी instead of ईज़ी.
2. Another common example of this is the fruit name “Banana” that’s incorrectly transliterated as बनाना (16 Million search results) instead of बनैना (3000 search results). The two “na” next to each other don’t have identical pronunciations!
3. The American state of New Jersey is commonly transliterated as न्यू जर्सी (250,000 search results) while the correct pronunciation is न्यु जर्ज़ी (5 search results).
4. There are scenarios where a minor variant might reflect the sound more accurately, for example, if “pen” is incorrectly translated as पेन, a more phonetically accurate one will be प्हेन where “ह्” is reflecting the air puffs at the beginning.
5. The reverse happens where the silent “h” sounds are transliterated creating sounds that shouldn’t exist. For example, the word “ghost” is incorrectly translated as घोस्ट (600,000 search results) while it is pronounced गोस्ट (80,000 search results). The घ sound is non-existent in English. This mistake probably happens because the Hindi words containing घ, for example, मेघा are transliterated to gh. A similar mistake happens in the word “Thai” that’s incorrectly translated as थाई instead of टाई or more accurately ठाई. Also, note that ठ should be pronounced like ल without doing a retroflex (tongue-curl).
6. A more subtle example is when the same word has different pronunciations, for example, record as a verb in “recording” and record as a noun in “for the record” is pronounced differently. The first is pronounced ऱिकौर्ड while the second one is pronounced ऱेकर्ड.
7. One of the worst examples of this mistake is the Spanish word junta which refers to a military regime. It is pronounced “hoonta”. Even major newspapers incorrectly transliterate it to जुंटा (130,000 search results) instead of slightly more correct हुंटा (450 search results) and correct हूंटा (0 meaningful search results!!!). Ask yourself, why should it be called जुंटा except for the fact that it looks like an English word and someone decided to treat its English spelling as proof of its pronunciation! A similar example is the Italian word pizza, the world’s most popular dish, that’s pronounced पीत्ज़ा (2000 search results) but is most commonly written as पिज्जा (3 Million search results). Even more accurate प्हीत्ज़ा word has no search results. Why should English spelling dictate the Hindi spelling of an Italian word?

Lack of syllable stressing

1. Hindi is spoken without stress. English as well as Spanish, however, uses stress for pausing and emphasizing particular letters. While stress is explicitly marked in Spanish, in English, it isn’t.
2. In the case of English, getting the stressing wrong makes it sound unnatural, while in the case of Spanish, it can change the word meaning completely. Consider, for example, oncologist, even its correct transliteration अङकॉलजिस्ट does not convey the full information, as one is expected to pause briefly after अङ and say " कॉलजिस्ट" as a single unit after that. One can bring back Sanskrit’s avagraha symbol to have a similar effect, अङऽकॉलजिस्ट. At first glance, this might look unusual but that’s because the previous spelling wasn’t conveying the full information, to begin with. A similar example is the name of the city of San José, which is incorrectly translated to “सैन जोस”. Again, being a Spanish noun, reading it as an English word is misleading. When one tries to translate the English pronunciation, the more accurate Hindi equivalent will be सैन होज़ेऽ. The ऽ emphasizes the stress on the last syllable.

Note

1. I used the term English to reference American English here. And Hindi to the north Indian Khadi ( खड़ी) boli dialect.
2. For the sake of completeness, I should mention that apart from labio-dental f and v, there is a labio-dental m as well. When m is followed by v or f, it transforms from being bi-labial to labio-dental, for example, the “m” sound in the word comfortable.
3. The Sanskrit sound ऋ is probably a retroflex r-sound and is the same as the English r sound. Most Hindi speakers pronounce it as रि though.