If we only speak to our child in English, will he lose his ability to speak in native language?

Yes. You will therefore need to decide if you want your child to maintain his skills in your native language. Consider your long-term goals. If you and your family will not return to your home country, maintaining the native language may not be a priority. Also consider your family situation. If extended family members don't speak English, it will be important for your child to maintain his native language so he can communicate with people closest to him. Also consider how your child might feel about losing his native language and a sense of his cultural identity when he gets older.

Excerpt from "Learning Two Languages." Reprinted with permission from PBS Parents.