In the world, over 7,000 languages exist. Having foreign background, moving to a foreign country, whatever the reason may be, you may be required to learn another language. Learning a language, while it does take time and commitment, can easily be learned with the right technique and keys. Once these are mastered, the time portion may be reduced. I will use examples from languages I am learning to give you an idea. The first thing that is vital is understanding the grammar. After grammar is understood, the other things are much easier to piece together.
Grammar is the largest piece of the puzzle in language learning. Knowing where certain words go where in a sentence can be extremely difficult. Most languages have grammar cases, most of the indo-europian languages uses cases such as nominative, accusative, dative, ablative, genitive, vocative, and locative. Using German as an example, as it uses four cases, it is easily mastered once knowing the differences between each. For example, "Das ist der Name des Mann." (That is the name of the man). Der Mann, which is masculine, changes in the genitive case to des. When speaking in the accusative form, der changes to den. "Ich habe den Hund." (I have the dog) changes the masculine der to the accusative masculine den. Another thing that is a bit tricky when learning a language are the articles. Almost every language except for English has articles, whether it be masculine and feminine (and) neutral, etc. Using French as an example, "la soif" means "the thirst" and "le même" means "the same". La is feminine and le is masculine; in addition, a language has a plural form of an article, in French it is les as in "les pâtes" meaning "the pasta". As it may take a long time to master grammar in a language, however once learned, the rest of the language comes pretty easily.
Vocabulary is another key part of language learning. Having a wide range comes over all pretty easily; the easiest way to build up your vocabulary is to look around you or pick scenarios and ask, "What is the meaning of that word in (insert language here)?" For example, when learning Spanish, in the kitchen, while making dinner, you may ask yourself what the ingredients you are cooking with are in Spanish. It is easiest to write a list and later on, write them down. So if you're making chicken and beans, next time you cook that meal, you'll remember that you are cooking el pollo y el frijoles.
Speaking, reading, writing in another language is or can be extremely difficult at first. It is very important when learning to start speaking from day 1. This means even if you only know how to say "hello" in that language, do it! It helps immensely when learning; it helps with memory, familiarity (so you don't feel this is such a foreign concept), and also, your accent. Another way to help out with pronunciation and minimizing an accent is to listen to music, watch TV, listen to the radio, and read out loud, entirely in that language when possible. Even if you don't know what half of it means, reading something such as "Aku (Saya) pergi de sekolah" (I am going to school) because it also helps you master grammar. The only way to learn pronunciation is really to listen, otherwise you may not know that the pronunciation of "il cane" (the dog) as opposed to "la obliteratrice" (the ticket validator). Reading and writing can especially be difficult in languages such as Arabic or Russian. In Bulgarian, it becomes more challenging because not only do you have to know the transliteration, but also the pronunciation and meaning, such as in "производна" meaning (the derivative). If you're willing to try hard enough to learn a language, however, you will find it beneficial and you do, whether you think or not, have the potential to do it, if you want to.
In conclusion, while a language takes time and effort to learn, it can indeed be accomplished with work and commitment. The key things to focus on are grammar, vocabulary, speaking (including slang), reading, and writing. Once these are mastered, you will pretty much be a pro at speaking your choice language. Good luck!