Speech development: Cooing (2-3 months), laughing (3-4 months), babbling single sounds "ba ba" (4-6 months), babbling with variety "ba da ma" (6-9 months), first words around 12 months. Babbling is practice for real words! Babies experiment with sounds and learn language rules by listening and repeating. Responding to baby's sounds encourages more talking. Have 'conversations' by mimicking sounds back.

Crawling typically starts between 7-10 months, but range is wide (6-12 months is normal). Many styles: traditional hands-and-knees, army crawl (belly on floor), scooting on bottom, crab crawl (backward first). Some babies skip crawling entirely and go straight to walking - this is normal! Once mobile, serious baby-proofing is essential. Baby can get into dangerous areas quickly.

Hand-eye coordination develops gradually: Batting at objects (3 months), purposeful reaching (4 months), grasping successfully (5-6 months), transferring objects between hands (6-7 months), pincer grasp (8-10 months). Early reaching is inaccurate - baby swipes at objects and misses. With practice, becomes more precise. Grasping starts as whole-hand "raking" motion, progresses to thumb-finger pincer grasp. Crucial for self-feeding, playing with toys, and later writing skills.

Object permanence is understanding that things continue to exist even when you can't see them. Develops around 4-7 months, fully established by 8-12 months. Before object permanence: Baby thinks objects cease to exist when hidden ("out of sight, out of mind"). After: Baby knows you still exist when you leave the room, will search for hidden toys. This cognitive leap explains why separation anxiety starts around 8 months - baby now knows you exist elsewhere and misses you!

Most babies roll tummy-to-back first (2-5 months), then back-to-tummy (4-6 months). Rolling both directions usually happens by 6 months. Once baby can roll, they may do it constantly - even during diaper changes! This is normal development, not defiance. Safety becomes critical once baby rolls - can roll off elevated surfaces or onto tummy during sleep.

Sitting development: First sits with support (4-6 months), then sits without support briefly (6 months), then sits steadily and pivots (7-9 months). Babies usually master sitting before crawling. Opens up new ways to play and explore! Strong core muscles from tummy time help with sitting. Toppling over is normal when first learning - provide safe space with soft landing.

Start tummy time from day 1! Place baby on tummy on firm surface for short periods while awake. Builds neck, shoulder, and core strength needed for rolling, crawling, sitting. Start with 2-3 minutes, 2-3 times per day. Gradually increase to 15-30 minutes total by 3 months. By 4-6 months, baby should tolerate longer periods. Many babies hate tummy time at first - normal! Keep trying. It gets easier as they get stronger.

Many babies hate traditional tummy time (face-down on floor). Good news: There are many alternative positions that build the same neck, shoulder, and core muscles. Why babies resist: Tummy time is hard work! Requires muscles they're still developing. Some babies have reflux making it uncomfortable. Some just prefer seeing faces. Goal is building upper body strength - doesn't have to be traditional position. Even resistant babies can get tummy time through creative positioning.

Newborns see clearly about 8-12 inches away (perfect for seeing parent's face while feeding). Vision develops rapidly in first year. Milestones: Tracking objects (2 months), recognizing familiar faces (3 months), depth perception (5 months), full color vision (7 months), seeing across room clearly (12 months). Babies are naturally drawn to high-contrast patterns, faces, and movement.