When you have a though or feeling, but said since your mother language is Chinese you can’t express it in English. So for a baby when he can’t talk he can’t express himself, do those thoughts exist.
Discussion
People always say children could pick up a language quickly than an adult. I feel that because children know little about the world and when he learns language, he basically intuitively link that thing/ thought with the language, while an adult is almost doing the translating job. So when you already shape your value using a specific kind of language, it could be hard for you to learn and use another language just as the initial one, it may can but takes a lot more time.