A: A. First, there's more to language development than just speaking (known as expressive language skills). There are also receptive language skills, which involve your child understanding what you're saying to her, even if she doesn't talk back. Since your daughter responds to you in sign language, her receptive skills appear to be fine, which is a good indicator that her speech may be okay as well. That said, kids this age should have a lot more words than just the simple few you mentioned. As hard as it may be, you should discourage your child from using sign language for a while, which will help you figure out whether her speech is truly delayed or if she just prefers to communicate with signs. For example, don't respond if she signs for words like "up" or "mama." Then as she learns to say new words, eliminate the signs for them as well. It's important to phase sign language out slowly, so your daughter doesn't feel as though it's a punishment. As you eliminate signing, your daughter's speech should steadily improve, but if it doesn't you should probably have her language skills evaluated. If it turns out that your child's speech is delayed, don't fret. When caught at this young age most issues can be addressed with early intervention.