open a conversation (with one)
To begin a speaking with one; to strike up a conversation with one. I just find it so hard to open a conversation with someone I don't know. They kept getting interrupted every time they tried opening a conversation.
open a conversation
to start a conversation. (See also strike up a conversation.) I tried to open a conversation with him, but he had nothing to say. She opened a conversation with an inquiry into my health, which got me talking about my favorite subject.