When will i know if my baby is right or left-handed?

Toddler: Most babies will begin to show a hand preference in their toddler years, but most children will not definitively show that strong preference until they begin to write well independently.

Be patient: Although some researchers suggest an infant may use one hand more than another as early as 6m, most describe true hand dominance as emerging between 2 & 4 yrs. I worry when a child uses one hand more often before a year as it can be an emerging sign of a motor impairment as seen in cerebral palsy.