Structure
It is very common in English to put two nouns together without a preposition.

• tennis shoes    
• a sheepdog    
• the car door    
• orange juice

The first noun is like an adjective in some ways.

Compare:

• a race-horse ( = a sort of horse) a horse-race ( = a sort of race)
• a flower garden  ( = a sort of garden) a garden flower  ( = a sort of flower)
• milk chocolate    ( = something to eat) chocolate milk    ( = something to drink)

We often put small questions at the ends of sentences in speech.

• That's the postman, isn't it?    
• You take sugar in tea, don't you?
• Not a very good film, was it?
  

We use these 'question tags' to ask if something is true, or to ask somebody to agree with us.

Structure

We do not put question tags after questions.

        In 1946, Winston Churchill traveled to Fulton, Missouri, to deliver a speech and to be present at the dedication of a bust in his honor. After his speech, an attractive and ample woman approached the wartime prime minister of England and said, “Mr. Churchill, I have traveled over a hundred miles for the unveiling of your bust.” Churchill, who was known far and wide for his quick wit, responded, “I assure you, in that regard, I would gladly return the favor.”

        Parallel structure means putting ideas of the same rank in the same grammatical structure. In the above anecdote, the italicized words and phrases show parallel structure. Your writing and speech should have parallel words, phrases, and clauses. Parallel structure gives your writing many admirable strengths, including tempo, stress, balance, and conciseness.

There are four sentence functions in English: declarative, exclamatory, interrogative, and imperative.

1. Declarative sentences state an idea. They end with a period.

• Grasshoppers contain more than 60 percent protein.
• Insects are rich in necessary vitamins and minerals.
• Crickets are packed with calcium, a mineral crucial for bone growth.
• Termites and caterpillars are a rich source of iron.