There is a large body of research that shows that speaking your primary home language(s) is most beneficial for your child – whether or not they have delays in speech, language, or communication. Building the foundation skills for communication occurs in the same way in all languages. That is, building an understanding of the words you hear, developing an expressive vocabulary/word bank, using sounds/single words to communicate, building phrases, etc. all occur in each language. Rather than having a negative effect, hearing and using multiple languages has an additive effect. It is also important that your child be exposed to the specific speech sounds in your home language(s) as there is a critical acquisition period for those sounds and if your child is not exposed to and practice saying some of the sounds that are unique to a specific language then they will lose that ability and will not be able to acquire this skill when they are older.