Baby Development: 18 to 21 Months

If your 18- to 21-month-old has taken on a whole new personality, fear not -- that’s actually very normal. Your baby’s newfound sense of independence during her second year of life is natural. Look out for these baby milestones during this stage of development.

Walking and running

Most babies learn to walk without help between 9 and 17 months, so by 18 months your baby will probably be cruising. This means it’s extra important to make sure your home is baby-proofed for your newly mobile child. And beware: About six months after your baby learns to walk, she’ll most likely be able to run. Get your sneakers ready!

Soon after the running starts, your baby will discover a whole new activity: climbing. “Up” may become her new favorite word, and suddenly everything in your house will be fair game for climbing, from the furniture and stairs to the dog and your leg. Now would be a good time to invest in some baby activities that involve climbing.

Even if you’ve had playdates before, it’s unlikely that your baby actually knew what to do with the new friend by her side. All that will change during these months. Look for your child to start paying attention to, and even associating with, the children she comes in contact with now. She may not be ready to take turns or share just yet, but she’s on her way to getting there.

Pretend play

Pretend play is important for your baby’s development and imagination, and between 18 and 24 months, this type of play will really kick in. Around this time, you may find your toddler babbling away to her stuffed animals or feeding her dolls. Encourage your child to use her imagination by choosing toys like costumes, dollhouses, and pretend food

Baby speech development is abundant between 18 and 21 months. Whereas before, your baby may only have been able to murmur or mimic you, at this age, you can expect simple phrases like “I’m done” and other short sentences. Engage in baby play and activities that help develop your baby’s newfound sense of language, like playing telephone or taking turns “reading” a book.

Keep in mind, a lot is happening with your baby between months 18 and 21. While you may be surprised at her newfound sense of independence and how fast she’s growing, just remember that all these milestones mean your baby is developing beautifully, and that she’s right on track.