DS is 21 mths and really only says one word which is DD's name (but this is a v simple 2 syllable word). Doesn't say mama/dada etc. He does babble quite a lot and is v communicative in other ways so often makes himself understood. Also, I have no concerns about his hearing because he understands most things I say to him.
DD was already repeating words at a year old and seems to have not stopped talking since (she's now 4).
I'm not worried about DS's lack of speech yet (she says tentatively!) but wondering at what point I should be visiting the HV to seek some help?