Learning a foreign language is rarely a simple thing. You have to learn tonnes of new vocabulary and words that may hardly resemble anything you've ever seen before. Then there are false friends, the words that look or sound exactly like words in your own language, but have a completely different meaning.
Even then, when you learn a few words, the syntax may be completely different to the syntax in your own language. In this case, you have to train your brain to recognise this in order to make yourself understood and to understand what you read and hear.
Then there's the grammar. Some people can learn grammar with little effort. Then there are people like me, who even struggle with grammar of their mother tongue.
In addition to almost completely changing the way you think, you also have to learn how to pronounce all the phonemes in a language. Learning to use an authentic accent in a foreign language can be difficult if your mother tongue doesn't share many of its phonemes with those of your new language.
It's unlikely that you will gain all this knowledge and all of these skills overnight. Just like learning a musical instrument, there are going to be a few wrong notes here and there. That's not a problem.
Making mistakes and learning from them can be one of the most useful tools in your language learning arsenal. The worst thing you can do is not talk or practice your new language just because you're scared of making a mistake.
Sometimes mistakes can be embarrassing, but in my experience, most people that I've met have always been very understanding to those learning a language. In fact, some of the errors I've made in the past have been amusing, such as telling an older lady that I was horny when I meant to say that I was warm, and telling a friend that I had diarrhoea when I wanted to say a cold. I've never made either of these mistakes since.
So if you're learning a language, don't worry! Make mistakes and learn from them. The improvements you'll make will far outweigh any embarrassment you may suffer from making mistakes.
What's the worst mistake you've made in a foreign language? Tell us about your experiences in the comments below.