Let’s see one of the most used words in English: The. T has the sound as in tee, trunk and toe. H has the sound as in hope, heal, and hide. Th is not t + h, rather it is a missing consonant in English. Please give your tongue a good look to see how exactly you pronounce.
Then there’s the famous replacement of s with z but written as s when in between vowels. Eg. Isotope. Just write a z since you have the consonant. A point which Mauritius creole graciously makes use of to pass over some redundant French rule.
There is the famous r. Tare and tree give two completely different ways of pronouncing r. You are supposed to find out by yourself. The r in tree is same as in redundant, rose, river and try. The r in tare is the same as in tore, azure, bear and flair. It’s a consonant with 2 pronunciations which as in other cases hides the fact that English misses yet another consonant. Masquerading the lack behind rules does not help.
Despite the very scientific approach of Englishmen to many subjects, the teaching and learning of English is and remains an approximation.