One word said where it wasn't supposed to be, one sound heard in the wrong way. All of these can cause major problems so this is a big pitfall of language. Not everyone talks the same way and not everyone hears things in the same way, and this is how misunderstandings come about. If you hear, 'Meet me at eight by the water fountain' and you show up a 8 am instead of 8 pm there could be problems. If someone asks you a question and you say no, sometimes they need to ask you if you meant no to them or to the question.
Language has lots of holes and bobbles wrong with it.
Nothing is perfect but don't complain about what you have, it's a whole lot more than what most creatures have.