We can think about this question briefly, and then look at the following example (pay attention to the analysis of the underlined part): How much do you think he earns? How much do you think he earns? (object) How many books can you guess he bought the other day?

We can think about this question briefly, and then look at the following example (pay attention to the analysis of the underlined part):

How much do you think he earns? How much do you think he earns? (Object)

How many books can you guess he bought the other day? How many books can you guess he bought the other day? (object)

Who do you think the composer is? Who do you think the composer is? (Subject complement)

What do you believe is the most important thing for us to do in order to learn English well?

What do you believe is the most important thing for us to do in order to learn English well?

What do you believe is the most important thing for us to do in order to learn English well? (Subject)

Who do you think he is? Who do you think he is? (predicative)

How long are you sure they had known each other before they got married? How long have you been sure they had known each other before they got married? (Adverbial)

Which do you think tastes good, the chicken or the fish? Which one do you think tastes better, chicken or fish? (Subject)