"Very young children learn best through two-way communication. Engaging in back-and-forth "talk time" is critical for language development. Conversations can be face-to-face or, if necessary, by video chat with a traveling parent or far-away grandparent. Research has shown that it's that "back-and-forth conversation" that improves language skills—much more so than "passive" listening or one-way interaction with a screen."
Personal Note: Healthychidren.org has a wonderful series of advice for parents. I have saved each of them and have made them available at this link.