Q&A: Several ways to ask a question

My Hiknow student C.C. asks:

Hi Joe,
I have a doubt about the question:

• What are characteristics a person needs to start and run a business?

This sentence is from the phrasal verb lesson "Business - starting and doing business".
I'm not sure of the grammar here, because I would ask:

• What characteristics does a person need to start and run a business?

I mean I would change the "are" to "does". I don't know if I'm right or not.
Best regards

My answer:

Your sentence is correct. And so is the other one. They're both right, just different structures.
I believe the grammar of the questions might become clearer if I give you not only a grammatical explanation of the questions, but also example answers to the questions in the form of complete sentences.

I'll use a colour code to help demonstrate the grammar.

• Bold red = subject of sentence
• Bold green = main verb of sentence
• Bold purple = direct object or predicate of main verb
• Pink = indirect object of the main verb
  
• Gold = a clause or phrase that gives more information about another part of the sentence

1.

• What are characteristics [that] a person needs to start and run a business?
• Passion and intelligence are characteristics [that] a person needs to start a business.

2.

• What characteristics does a person need to start and run a business?
• A person needs passion and intelligence to start and run a business.

In Question 1:

•  "what" is the subject
•  "are" is the verb
•  "characteristics" is the predicate of the verb "are"
• "a person needs to start and run a business" is a defining relative clause about "characteristics"

The defining relative clause (more info) makes the question not about all characteristics that exist in the universe, but only about ones needed to start a business. This defining clause could start with "that..." but you don't have to have it.

In Answer 1,

•  "Passion and intelligence" is the subject

•  "are" is the verb
•  "characteristics" is the predicate of the verb "are"
•  "a person needs to start and run a business" is a defining clause about "characteristics"

In Question 2:

•  "a person" is the subject
•  "does... need" is the verb
•  "what characteristics" is the object of the verb "does... need"
•  "to start and run a business" is an infinitive phrase that is the indirect object of the verb "does... need"

Infinitive phrases (more info) can be used many ways. Here it's the indirect object of "does... need".

In Answer 2:

•  "a person" is the subject
•  "needs" is the verb
•  "passion and intelligence" are the object of the verb "needs"
•  "to start and run a business" is an infinitive phrase that is the indirect object of the verb "needs"

I'll also give a third possibility :D

3.

• What are characteristics needed to start and run a business?
• Passion and intelligence are characteristics needed to start a business.

In Question 3:

•  "what" is the subject
•  "are" is the verb
•  "characteristics" is the predicate of the verb "are"
•  "needed to start and run a business" is a past participle clause describing "characteristics"

Participle clauses (more info), using either past participle (usually -ed) or present participle/gerund (-ing), are similar to relative clauses, giving more info about another word in the sentence.

In Answer 3:

•  "Passion and intelligence" is the subject
•  "are" is the verb
•  "characteristics" is the predicate of the verb "are"
•  "needed to start and run a business" is a past participle clause describing "characteristics"

Oh boy, I just though of a fourth way!

4.

• What characteristics are needed to start and run a business?
• Passion and intelligence are needed to start a business.

In Question 4:

•  "what characteristics" is the subject
•  "are needed" is the verb, in passive voice
•  "to start and run a business" is an infinitive phrase that is the indirect object of the verb "are needed"

In passive voice (more info), the subject receives the verb, so there is no direct object.

In Answer 4:

•  "Passion and intelligence" is the subject
•  "are needed" is the verb, in passive voice
•  "to start and run a business" is an infinitive phrase that is the indirect object of the verb "are needed"

So you see, there's more than one way to ask a question! I hope that makes clearer for you these different possibilities.