What age did your child start asking 'why' questions

[sunshinedaises]

My ds4 has just started asking 'who's this' and what's that' along with some 'why' questions. I'm just curious what age your child did this (if they did) as my ds is very speech delayed so I'm hoping this is a good sign development wise for his speech

A few months before 3 years old. I’d say it’s a good sign that he’s now asking why. It’s a more complicated question than who or what, so he’s obviously starting to think about things more deeply. The endless whys get tedious pretty quickly though!