the stress pattern of the word is essential, then remember that consonnants play a great part in the way vowels are prononced. - if a vowel is followed by two consonnants, the vowel will be short. - if -ed follows a strong consonnant, then it can only be prononced "t". etc... it's a very interesting question, and it would require a very long answer. Whole books deal with that subject. But you will also learn to pronounce new words simply by practising, through analogy with other words, etc. Also, read new words out loud, you'll find that often, there's only one way to actually get them out lol And when you're stuck, dictionaries and websites are your best friends.

Of course, you can get a correct answer by finding the pronunciation in a dictionary or checking a site such as forvo.com or howjsay.com. It is quite possible to make an educated guess at pronouncing the word. For example, if the word is a little long and has a "ge" syllable in it, we can guess the word might have a French/Latin origin and therefore the "g" is soft, not hard. There are usually clues that we can recognise.

Yes, this is true. English is not spelled phonetically. Google Translate and most online dictionaries will pronounce words for you, though.

If you would like a very detailed way to learn any word, in any language; you should review the International Phonetic Alphabet (IPA). The IPA is a standardized representation of the sounds of oral language. If you would like a simpler answer; the English language can be learned using phonics. Phonics is a method for teaching English reading and writing by developing a person's phonemic awareness. I apologize for the short answer. There are other temporary methods to learn a single word that may be quicker, but these are meant to concrete the fundamentals.