Language shapes the way we think. Whether we're listening to a speaker or engaged in a conversation, language can introduce us to new ideas, perspectives, and opportunities.
But at a more fundamental level, language might physically alter your mind. Bilinguals, for example, have denser gray matter in their language centers than monolinguals. Bilinguals can more easily focus on two tasks at once. They think more analytically. Parts of their brain devoted to memory, reasoning, and planning are larger than those of monolinguals.
Learning a second language is like a workout for your mind. The benefits of bilingualism, from increased creativity to the delayed onset of Alzheimer's, should encourage everyone to pick up a second - or third! - language.

For bilingual speakers, from the first syllable they hear, their brain is working to identify the word, and the listener's brain begins identifying any words, in either language, that could fit the sounds as they arrive in sequence. Having to distinguish between two languages can be tricky in some situations, but the brain's executive functions, especially the attention and inhibition processes, are strengthened through this process, ultimately making bilingual speakers better at switching between two tasks or handling tasks that require conflict management.
Because the language centers in the brain are so flexible, learning a second language can develop new areas of your mind and strengthen your brain's natural ability to focus, entertain multiple possibilities, and process information.
Neurologists are reporting in the largest study to date on the link between language skills and the brain-destroying disease that people who spoke two languages staved off dementia years longer than people who only spoke one language.
A key way to avoid dementia may be learning another language. People who speak more than one language and who develop dementia tend to do so up to five years later than those who are monolingual, according to a study.

There’s more evidence that speaking a second language can delay the onset of dementia later in life. Conducted in India, the largest study of its kind so far found that speaking two languages slowed the start of three types of dementia — including Alzheimer’s disease — by an average of 4 years. “Being bilingual is a particularly efficient and effective type of mental training,” said Dr. Thomas H. Bak, a researcher at The University of Edinburgh. “In a way, I have to selectively activate one language and deactivate the other language. This switching really requires attention.” That kind of attention keeps the brain nimble and may ward off not only Alzheimer’s disease, but other cognitive conditions such as frontotemporal dementia and vascular dementia, the new study found. The researchers examined case records of 648 patients with dementia who entered a memory clinic. Slightly more than half of the patients, some 391, spoke more than one language in a place where many people grow up learning three or more languages, including Telugu and Dakkhini along with English and Hindi.
“It really brought up the question, is it the bilingualism or is it is being an immigrant?” he said. “They have very different lifestyles, very different diets, which can affect the outcome.”
Still, those studies also found that speaking more than one language delayed dementia by the same span of time, four to five years.
“If I live in Hyderabad, I will be practically always switching,” said Bak. “There will not be a day when I don’t have a chance to practice.”
The researchers found that patients who spoke a single language developed the first symptoms of dementia at age 61, versus age 65 in those who were bilingual. The delay was slightly more than three years for Alzheimer’s disease, but about six years for frontotemporal dementia and about 3 years for vascular dementia.
In people who couldn’t read, the delay of dementia was about six years later in those who were bilingual versus those who spoke only one language — evidence that education isn’t the key in postponing problems, the researchers said.
The effect of bilingualism on dementia onset was independent of other factors including education, gender, occupation and whether patients lived in urban or rural areas, the authors said.
Speaking more than two languages didn’t appear to increase the effect, a result that surprised researchers, Bak said. Other studies have found that the more languages spoken, the greater the protection against dementia.
It’s still not clear exactly how language acquisition triggers protection against dementia, or whether another kind of intense brain activity such as learning an instrument or doing puzzles could mimic the effect.