I happen to have a child who remembers very little of what I say, especially if said child is engaged in something other than giving me his undivided attention, which is often. If I throw in the word "baseball," or "ice cream" he perks up, but only for a short moment, until he discovers my decoy.
Giving him one instruction at a time, or writing a list is always best if I want results. I let him check off the list when tasks are completed and keep a personal list when he has schoolwork to accomplish. “Make your bed” and “brush your teeth” are a poster size list that never changes.
He isn't a big talker about school, friends, or church either. His word count is incredible low. I have found that the best way to gather information is to get him one on one. With siblings in the mix this often poses difficultly but with some strategic Tetris maneuvering I succeed.
Beginning with subjects that interest are best. "Do you think the pitchers should be required to hit as well?" or "When is the best time to use a driver in golf?" get the vocal chords lubricated for the real conversation and questions like "What happened to your grade in language arts?" or "Why don't I see Luke around anymore?" One-word answers are his specialty so I construct open-ended questions for greater results.
For adult children, the same is true. If I want to have worthy conversation I need to discover their communication style and timing. Do they prefer e-mail or phone conversations? Do they respond to text message or a message on Facebook? While one child gives little information when he is hungry, another rattles on endlessly when we take the dogs for a walk. My daughter has unique timing. She could talk for hours at 10:30 in the evening or right in the middle of the workday, inconvenient at best, but rarely shunned.
Talk, converse, share, collaborate, seek, and ask, but always keep the conversation going. Do what works best for their style; feed them, take them on a date, make a list, send an e-mail, draw a picture, play a card game, or go for a bike ride. Fight through the grunts and groans, push away the one-word answers, encourage, question, and consult. Getting some children to talk is tough, but it is rarely impossible, unless you begin with a bullhorn.