Because I usually see the pattern of men not speaking up and women probing repeatedly to find out what's wrong (because she can tell there is something bothering her partner), I'm going to use she and he in this column. Of course there are couples in which it's the silent woman and the man is trying to figure out what's up.
Let's look at this from each partner's perspective. We’ll start with the man not speaking up. Why is it that he doesn't let you know what's on his mind and in his heart? Is he unclear on his feelings? Is it just how it was done in his family? Is he purposely holding back? If so, how come? Is he embarrassed? Are things moving too fast for him? Is he worried about your reaction? Does he feel afraid of conflict, or starting a fight if he does speak up? Might he lack self-confidence? Is it that he doesn't want to feel exposed or vulnerable? Is the power in your relationship out of balance? Does he lack power? Is his not telling you a power-play?
Healthy indicators of power: Letting you know who he is and what he has to give and share. Unhealthy power is wanting, or having power over your partner, or to keep him or her off-balance.
Women, what can you do to help make it easier for him to share his thoughts and feelings? Many women believe they are good listeners, and then over time they tell me they're not as good at it as they thought they were. Consider an experiment with things that may help (e.g., not contradicting, not getting angry, not dismissing, etc. It doesn't mean you have to agree!).
Now let's consider this from the guessing/probing partner’s perspective. Often she's willing to do this early in the relationship, or he talks more early on. Yet over time she tires of the pattern. It becomes a lot of work for her. Also her guesses are likely to be inaccurate. She may become resentful of the amount of work it becomes, and she'd like you to just say it. Does the strong, silent type show love and communication in other love languages?
Men, is this really what you want to be putting your partner through? Even though it's not intentional, this is still the impact it often has. Talk to her before she tires of it enough to decide to stop trying to pry it out of you altogether – because now your marriage is really in trouble.
The truth is a lot of men and women just didn't learn how to talk about their feelings, thoughts, needs, and wants growing up. The good news is you can still learn.