Ok, here's the good news: homophones (words that sound alike) aren't as common as one thinks.
Which means, for example, words with silent letters, eg. "gh", normally don't sound like any other word. Night, fright, ought, though, etc all use the silent gh (and have a long vowel), but there's no other words they sound like.
And for an example like "eight/ate" (identical sound), you work it out from context: "I ate eight" makes sense; "I eight ate" makes very little sense.
For the rest... well it is a case of getting to know the word's spelling and pronunciation. If you can read the dialogue while you hear it, that will help a lot. Follow the spelling only as far as it is useful. Trying to follow it to a perfect logical confusion is what confuses students.