When learning a new language, or indeed when acquiring any new skill for that matter, one will inevitably make mistakes. The first, and most important thing, to understand is that making mistakes is a perfectly normal and natural part of the process, even the most naturally gifted linguists make many faux pas while they are honing their abilities.
While many of us don’t realize it, we often make many mistakes in our native language when speaking and writing. But once outside the school system, these are rarely picked up. Therefore, the idea that you will ever totally perfect a language isn’t feasible. That isn’t to say that you can’t reach a stage where you are of native fluency, but inevitably there will always be error and this is perfectly normal.
The process of allowing yourself to make mistakes is a very important step in the learning process. Essentially it gives you an indicator of what you need to focus more on. Only by accepting that you have points of weakness can you identify them and correct the problem, if necessary. Therefore it’s important to push yourself, allow mistakes to happen rather than totally sticking to what you know where these problem areas can not be flagged up.
An important question that you most always ask yourself if you make a mistake is, does this mistake really matter. Of course there will be times when it does, but more often than not you’ll find it won’t necessarily have an impact on your fluency; this is especially true at intermediate level. If you want to study in another language then grammar and composition will be very important. However, for most learners this is not the case. If your main goal is to be understood in general conversation, say in a restaurant, and you confuse the verb, noun order, if your point is understood does the mistake actually make a difference?