“Has {child_name} started using words like 'me' and 'you' in roughly the right way — 'me want biscuit', 'you do it'?”
Follow-up: “Are the pronouns matching who means what, or still a bit mixed up?”
Not yet
Doesn't use pronouns yet — refers to everyone by name
Emerging
Uses 'me' or 'you' occasionally, sometimes mixed up
Developing
Uses personal pronouns regularly, mostly correctly
Secure
Uses me, you, mine, yours correctly in everyday talk
Pronouns are genuinely tricky for toddlers — mixing up 'me' and 'you' is completely part of learning them.