If you're older than 10 and want to learn a second language, we've got some bad news.
A new study from the Massachusetts Institute of Technology (MIT) has shown it's nearly impossible to become completely fluent in a second language unless you start before the age of 10, MIT News reported.
While those who start between 10 and 18 will still learn quickly, they have a shorter window before their learning ability declines, the research said.
Assistant professor of psychology and study author Joshua Hartshorne said if someone wants to have native-like knowledge of English grammar then they should start from before they hit 10 years old.
"We don't see very much difference between people who start at birth and people who start at 10, but we start seeing a decline after that."
The findings looked at an analysis of a grammar quiz taken by nearly 670,000 - by far the largest data-set anyone has brought together for a languages related study.
The quiz, entitled "Which English?", was designed to challenge non-native speakers and was able to garner what age they begun learning.
"It's been very difficult until now to get all the data you would need to answer this question of how long the critical period lasts," study co-author Professor Josh Tenenbaum said.
"This is one of those rare opportunities in science where we could work on a question that is very old, that many smart people thought about and written about and take a new perspective and see something that maybe other people haven't."