You may find that they do not talk as quickly as some children but they are able to
understand both languages.
Yes I noticed, my older son is nearly 20 months old and say very few words, I talk with him exclusivery in french
(since he was born) and my husband and the other people here in England talk with him in English, yet he says
more french words than english, but he does understand absolutely *everything* either in french or english . I can't wait when he start talking so that i can have proper conversations with him :)
So, keep it up and do not let anyone tell you it is making it difficult for them.
sometimes I get worried, especially when I see how my son's playmates already talk more than my son

Aouali