How do someone study foreign languages and master it like a mother tongue?

in my opinion . reading books very much

in my opinion, to be able to master a language as if it was your mother tongue you need to follow three steps.First, you must be aware of the culture of that particular language country because one of the main aspects of learning a language the right way is through its culture background.Second, you certainly need to use that language more often if you wish to sound like a native speaker.Third, the most important aspect is to keep up with the language and be aware of all the updates.

it's simple way is to follow that language as you follow your own language (mother tongue).

Naturally the best way is to spend 6 months in the country where the language is spoken, a full immersion course, interact with the locals.

I managed to learn languages and mastered them well by listening to music, self teaching courses. and never was afraid to speak even if at the start I did lost of mistakes  

Everyday practicing is the main key to master a foreign language, you can watch movies and listen to music in that language as a fun way to study it, in addition to read books. besides, you can download language apps that can help you by giving courses. For those who can afford traveling, they can spend few months where that language is spoken in order to interact with the locals.

Practice

Browse the songs and movies programs in this language

Talk to people who consider this to be their mother tongue

Natural, my example usually mingles with a group of person try to understand what they are talking about in between depending upon the situation general explain then and ask for corrections slowly start a conversation. Almost 50% learnt by listening and 50% by starting conversations with them. Found they were glad to teach me their language.

We can able to catch any language but 100% dedication should be there

on the basis of reading books and newspaper, watching movies,

and whatever coming in our mind we should try to convert it into other language  

if you are continuing and using it daily

tous simplement apprendre et parlé avec cette langue courament meme si tu fait des erreurs.