A child that I mind has no words at all at 20 months, and doesn't really make any effort to communicate in any other way. For example he doesn't point at what he wants. If others are talking he will join in by screaming, but his most expressive noise is 'Uh'. He's been coming to me for a couple of days a week since January and there's been absolutely no change in his language development since then. He doesn't 'jargon' either. He has no problem with eye contact, so I don't think it's an autism spectrum thing, and he has no trouble hearing if I tell him it's snack time or whatever, so I don't think it's a hearing issue either. His parents don't seem at all concerned, but I'm beginning to be. Would you say something?