Bilingual child

Talk to your child at home using your native language. Enroll your child in a school which promotes other language to speak inside their facility like chinese or english.

I think the best way is to teach your child a sign language. Since you're in Romania, I suggest French Sign Language since that is the most commonly used sign language and the base for many of the sign languages out there. Basically your child will associate a meaning to a sign and they can say the word in different languages while signing the same action. It helped me to learn German.

Marry a partner with a different native language. Talk to the child in your respective languages. It'll take a bit longer, but the child will soon be fluent in both languages.

I think there should be constant need to speak the language and then a child, or anyone, can speak even many languages. They are like a sponge able to observe and absorb all around them so much faster - siva