How much should she be talking?

[*LittleMissSummer*]

My DD is 20 months. On average how many words should she know, should she be speaking in sentences yet? eg, can i have a drink?

I swear my nieces and nephews were talking a lot more at her age than what she is. Or am i being unrealistic and expecting too much?

[Jellyfish]

I think the average for a 20month old is around 15 words. They might be starting to pair words but I think expecting proper sentences is unrealistic and more a 3yr old thing. Of course there will be some who are more advanced and it can be more common in second, third, fourth etc children to develop language at an earlier age.