At what age should student start learning a foreign language?

Broadly speaking, the younger you are, the more efficient your language skills can be. For example, I have a sibling who is mixed; her father is German and her mother is Thai. She picked up phrases from different languages quite quickly, even though she didn't have formal learning. Her parents kept talking to her, so [...]

Broadly speaking, the younger you are, the more efficient your language skills can be. For example, I have a sibling who is mixed; her father is German and her mother is Thai. She picked up phrases from different languages quite quickly, even though she didn't have formal learning. Her parents kept talking to her, so [...]