A language is not physics. There are no laws, only rules and exceptions. Observe the rules to get your ideas across or, if bold enough, cross that line to coin new utterances and set them free to live on their own hoping to root or risking to fade away. To your surprise, you may hear an expression you thought was yours from a person with no relationship or geographical link. This is because people of a nation nurture their language just living their everyday lives. Their language simply lives and breathes to the rhythm of their news and history.
A language is both scientifically abstract and immensely popular. My students often ask if they would be understood if they made a grammar mistake. The answer is resounding yes. That is because the priority of your audience is to understand you and your thoughts. Moreover, their minds start to predict the correct structures as soon as you begin to talk or write even though you may be grammatically inaccurate. You use something they have never known before and yet you are understandable for them. This is one of the unique qualities of a language that amazes me most.
A second language cannot be learnt, I am sorry. You must acquire it subconsciously. We, the teachers, know how to lead our students, and there are endless libraries of approaches, methods and resources available, but they have to do the hard work on their own. Invest all your talents and efforts and one day you will be rewarded with a certain scaled level of language acquisition, I promise.
Depending on the number of language pairs, translators often lead a double or multiple life with the insight into two or more cultures. Foreign languages are so inconsistent with mother tongues. They are so full of syntax and vocabulary traps and false friends. If your choices work fine, lucky you. But once you flood an international railway station with visitor instruction signs with bad translations based on your mother tongue routines, you are in trouble.
A language is the legacy our forefathers left us after having so selfishly changed the very essence of their lives into an utmost comfortable language which has stayed alive and kicking for many generations rolling on through ages continuously enriching and losing its structures, vocabulary and styles. Thank you very much indeed.
Next time you speak, or employ any other language skill, remember you are actually using relics and pronouncing the words people have been using for centuries to communicate all their messages, in love and war. How does it feel?
Feel free to enjoy all there is to a language but do not carve in stone without proofreading.