In many languages, words are pronounced in the same way they are spelt. That is why people who learn English often make mistakes in pronunciation and develop thick accents. As a result, they are being asked to repeat themselves which can be very annoying. I was there myself.
In English spelling and pronunciation are not identical. English inherited a lot of foreign words, including Latin, French, Dutch, and German and they kept the original spelling but anglicised the pronunciation.
For example, the sound / ʌ/ as in “duck” can be spelt with "o" in words “come, oven, front, company”, or with “u” in words “bus, lunch, pub” and with “ou” in words “ country, double, trouble”.
Another example is the sound /a:/ as in “father”. It can be spelt with “er” in words “Derby, clerk, sergeant” or “ar” in words “car, park, dark”.
Sound /f/ is usually spelt with “f” in words “ fake, fix, frame”, but it can also be spelt with “gh” in words “laugh, tough” or with “ph” in words “phone, philosophy, phobia”.
At the same time, words with different spelling and meanings may have the same pronunciation. Here are a few examples: one - won; soul - sole; steal - steel; mean - meen; write -right.
Many letters are silent in English. For example, silent /w/ in words “write, who, whimsical, wholesale”, or silent /l/ in words “walk, talk, chalk”, and so on.
The good news is that you can overcome this difficulty with apps based on RP where you can find spelling variations for all English sounds. When working with the apps, do not look at the spelling when you practise the sound for the first time to overcome the confusion in pronunciation. Listen and repeat the sound in words, phrases and verses. We had many students who despite knowing the fact that spelling is not the same as pronunciation kept reading in the same way as it was spelt because this was their habit.
I recommend starting with the app Elocution Lessons. Then follow up with the apps Get Rid of your Accent UK1, Business English Speech (British English) or American Accent App (American English) which were developed for advanced learners of English.
The same apps are also available on Google Play. They are based on bestselling books in the series Get Rid of your Accent. The functionality is ideal: read, listen, record and compare your speech with the model.
The apps contain:
1. Spelling variations for all English sounds,
2. Mouth diagrams to help you create the correct speech organ positions in words, phrases and poetry.
In all these apps, there is a link in “How to use this app” to the page: the difficult sounds typical for your nationality. Click on your nationality to work effectively with a more focused approach.