People who learn many languages can find it easier to learn more languages if the new language is like the ones they already know. But sometimes, learning a new language can be hard if the person remembers old languages they learned before. Sometimes, learning a second language can make it hard to remember words. People used to think that speaking two languages made you better at certain thinking tasks. But some new research says this isn't true. Those who speak two languages are better are not better at learning languages than those who only speak one. People who are very good at speaking two or more languages were once thought to have better thinking skills and get certain diseases like dementia later in life. But recent studies don't agree with this.