Babies and toddlers make amazing strides in mental, or cognitive, development during the first two years of life. They learn by looking, listening and imitating others. Parents and caregivers lay the foundation by encouraging their little one to expand her mental abilities, which include thinking, language, memory, understanding and reasoning.
0 to 6 Months
A 1-month-old is closely observing his parents when they talk to him. By 3 months, an infant babbles back with coos and squeals. He's also able to track noise by turning his head in the direction of the sound. A 3-month-old can distinguish between people and objects and tell the difference between a frown and a smile. By midyear, your baby is able to make vowel-consonant sounds like "ma-ooh." A 6-month-old clearly recognizes his parents and knows when he's seeing someone for the first time.
7 to 12 Months
A 7-month-old is physically able to sit up in your lap, reach for a book and give it his all -- alas unsuccessfully -- to to turn pages. By 8 months, your baby has become more vocal and says words like "mama and "dada," even though he doesn't yet know the meaning of what he's saying. In actuality, your little one is learning to combine syllables, points out the American Pregnancy Association. At this age, a baby understands the meaning of the oft-used word "no" but doesn't necessarily comply. A 10-month-old now knows what he's talking about when he says "dada" or "mama." "No," "go," "bye" and "hi" are commonly used words around this age. Patty-cake, peekaboo and other interactive games are exciting for a 10- to 12-month-old.
12 to 18 months
A 1-year-old is able to bring you a book to read, turn it right side up and hold it, notes the American Academy of Pediatrics. This is a good age to ask your young toddler to point to the dog, house, car or other pictures of interest in books. It won't be long before he'll correctly answer your questions. An 18-month-old toddler uses an object in place of another during "pretend" or "make-believe" play. For instance, she may use a washcloth for a hat or a pretend a cucumber is a telephone.
18 to 24 months
As a child gets closer to age 2, he may count out loud but not necessarily in the correct order. Toddlers in this age group love to scribble and are beginning to sort objects by color and shapes. A 2-year-old has an impressive vocabulary of about 50 words, uses a few adjectives like "small," "big," "happy" and "sad," and can put together some very short sentences, notes MayoClinic.com. She's also able to follow simple instructions such as "Get the book and bring it to me."