Here's the "Tidbit" part:
The average 1 year old has a vocabulary of around 100-200 words. (Though it may be in their own language that only Mom and Dad understand....you still know that "bebe" means bread.) Also, they understand about five times as many words as they can express themselves.
Here's the "Tip" part:
When you're speaking with your child, integrate new words. This will help their vocabulary grow. The more they hear, the quicker their vocabulary (their ability to both understand and say new words) will grow.
If you're at the zoo and your child sees a tiger and says, "Look, kitty."
Your response could be: 'That's a big cat, it's a tiger. It is orange and has black stripes."
This works with any age group of kids...gradually expanding their vocabulary by using words in a way they can relate to, but that they aren't always familiar with. If your child seems confused with the words you used, you can always restate the phrase in simpler words. You'd be surprised how much they truly understand though!