Once the cluster relations between sounds and letters have been established, there remains little to do on the input side. The ability to hear the sounds depends on the ability of the brain to associate the known chained sounds to the meaning of the word, something which requires practice. When heard enough after making a word-sound association, a learner will be able to hear meaningful things out of supposed gibberish. As far as reading is concerned, the letter-sound associations are the only things holding anyone back. Chaining the sounds while reading and correcting them according to what the word was intended to be pronounced as, will eventually make reading easier. Obviously, both input methods require solely your pattern recognition with the base of some prerequisite knowledge. The features hence incorporated into our base language, or the ‘grammar’ as we may call it, consists of the following: नाम(Nouns - Singular, Plural) सर्वनाम(Pronouns - 1st, 2nd, 3rd person) क्रियापद(Tenses - Past, Present, Future, Order) विशेषण, क्रियाविशेषण(base, comparative, superlative forms) विभक्ति(Case + Prepositions) विराम चिन्ह(Punctuation - Comma, Fullstop) Try it. Using only these grammatical features, use languages you have fluency in and analyse if it falls short anywhere. Test it out with other native speakers and see if they actually understand what you’re trying to say with this base form. I’m willing to bet that you won’t need any other tools at your disposal to communicate anything, even though you may be faced with unnecessarily complicated and tedious sentences. I’m not saying this is perfect, obviously there’s a lot missing here, but the subtleties they control are not enough to seriously mar human understanding. But if any one of the mentioned features is removed, the language can no longer support all possible situations that it should be able to support.