Speaking is so individual - DS has about 20 words, which he is currently neglecting for climbing - but his 22m old friend still doesn't say anything, aside from "aaaaaaaa" when he's having fun. At 12m DS had about 12 words, he likes to play with sounds more (like his mummy) so words come slowly, and he'll quite often use a word correctly, but then never use it again, so that doesn't go on his word count. If you listen hard you he can say about 3-4 words in a "sentence", but I'm not going to let him have that until it's very clear and obvious, although we can have a great conversation these days with him holding up his end really well.

Just keep talking, that's not being pushy, that's actually helping your child to speak. Quite often they don't know the words and that hampers them a lot.