The brain can learn a new word in less than 15 minutes, according to scientists, whose finding will rob many of the excuse that they can't learn a foreign language.
All one needs to do is listen to a word 160 times over that period, found Cambridge neuroscientists.
After that the brain will have formed a whole new network of neurons specifically tasked with remembering that word.
The process happens far quicker than previously thought, they found.
Dr Yury Shtyrov and his team made the discovery after placing electrodes on the heads of 16 healthy volunteers to monitor their brain activity.
First they recorded the pulses generated when they listened to a familiar word. Then the volunteers were made to listen to a made-up word, over and over again.
Initially the brain had to work hard to recognise the new word. But after 160 repetitions over 14 minutes, the new memory traces were "virtually indistinguishable" from those of the already familiar word, said Dr Shtyrov.
He said: "What this suggests is that practising language is important. Every little helps.
"Just perception - listening - is helpful. Our volunteers didn't repeat the words."
Getting them to repeat the words would "probably extend the new neural networks" to the part of the brain tasked with speech, he said.
However, he and colleagues at the Medical Research Council's Cognition and Brain Sciences Unit developed the approach, called constraint-induced aphasia therapy (CIAT), not to help tourists learn French, but to help stroke patients regain their speech.
He said: "This research suggests that faster rehabilitation may be possible if treatments for people with brain damage, such as stroke patients, target the brain’s ability to rapidly create these memory traces."
The next step was to test the theory in stroke patients, he added.
The research is published today (WED) in the Journal of Neuroscience.
Dr Shtyrov's method struck a chord with Paul Noble, a language teacher whose gets pupils to "forget" what they have just learned.
He thought repetition was the key - but the brain learned best when it was relaxed and not trying to remember anything at all.
He said: "If you follow sport, you remember all the players, the teams and the rules but you never intend to.
"You remember because you go back to it again and again.
"The mind doesn't choose to remember everything. If you remembered everybody you saw on the Tube, you'd go mad. It has to determine what's important and what's not."