The full form of WDYT is What Do You Think

“What do you think” is asking a person’s opinion. It has the same meaning as “In your opinion, “.

In your opinion, what is the most appropriate solution for this problem?

“What do you think?” usually means “What’s your opinion of this?” It’s typically heard after someone has put forward a proposal, or perhaps has completed some task, and is looking for approval or agreement, e.g. A: “I think we should go online, check the wallpaper on two or three different sites, and choose the one that most closely resembles what we already have. What do you think?” B: “Hmm. That sounds reasonable.”

However, “What do you think?” can have at least one other use or meaning (see ‘wallet’ example below).

“How do you think?” is, in my experience, a shortened semi-sarcastic reply to someone who questions how something might be done. It means, “Isn’t the answer obvious?” e.g. A: “I think we should get some wallpaper that looks like what we already have.” B: “And how do you propose we find that wallpaper?” A: “How do you think (we’ll find it)? We go online and check sites.”

This same sense of “Isn’t it obvious?” is found with other question words as well. We generally don’t pronounce the words in parentheses because we’re all familiar with how these sentences are used, but that’s what they mean:

(knock knock) A: “Who’s there?” B: “Who do you think (is here)? I texted you five minutes ago to say I was on my way over.”

A: “What’s that in your back pocket?” B: “What do you think (is there)? What do men usually carry in their back pocket? It’s my wallet.”

A: “I’ll be 34 years old tomorrow.” B: “So when were you born?” A: “When do you think (I was born)? I’ve just told you I’ll be 34 tomorrow. Do the math.”

A: “I don’t feel so good. I think it must be the leftover fish I ate last night.” B: “Why did you eat that?” A: “Why do you think (I ate it)? I was hungry and there wasn’t anything else.”