Two types of sentences in English are declarative sentences and interrogative sentences. Declarative sentences, or declarations, convey information or make statements. Interrogative sentences, or questions, request information or ask questions. Periods indicate declarative sentences in written English. Question marks indicate interrogative sentences in written English.
Declarative Sentences
Declarative sentences are subject-verb (SV) in word order. The subject comes before the entire verb phrase functioning as the predicate. For example:
Subject | Predicate
- Dogs | are super cute.
- My cat | is orange and white.
- He | ate lunch.
- That | rhymes.
- Franny | feels sad.
- Your aunt Bethany | wears red nail polish.
- His shoes that his mom bought him | have black and blue laces.
- I | have been baking a lot of cookies for the holidays.
- The neighbor’s dogs | had been being walked by someone new.
- Your packages | could have been being delivered while you were out.
Interrogative Sentences
An interrogative, or question, can be subject-verb (SV) in word order. A declarative question is a yes-no question identical in form to a declarative sentence but spoken with rising intonation at the end. A written declarative question ends with a question mark. For example:
- Dogs are super cute?
- My cat is orange and white?
- He ate lunch?
- That rhymes?
- Franny feels sad?
- Your aunt Bethany wears red nail polish?
- His shoes that his mom bought him have black and blue laces?
- I have been baking a lot of cookies for the holidays?
- The neighbor’s dogs had been being walked by someone new?
- Your packages could have been being delivered while you were out?
Prototypical interrogative sentences experience subject-auxiliary inversion, which refers to the movement of the initial auxiliary verb into the position before the subject. Sentences that contain only one verb that is not copular be take a do-operator that precedes the subject. Sentences with the copular be experience subject-verb inversion, which refers to the movement of a verb phrase functioning as the predicate into the position before the subject. For example:
| Declaration | Interrogative | Process |
| Dogs are super cute. | Are dogs super cute? | subject-verb inversion |
| My cat is orange and white. | Is my cate orange and white? | subject-verb inversion |
| He ate lunch. | Did he eat lunch. | do-insertion, subject-auxiliary inversion |
| That rhymes. | Does that rhyme? | do-insertion, subject-auxiliary inversion |
| Franny feels sad. | Does Franny feel sad. | do-insertion, subject-auxiliary inversion |
| Your aunt Bethany wears red nail polish. | Does your aunt Bethany wear red nail polish? | do-insertion, subject-auxiliary inversion |
| His shoes that his mom bought him have black and blue laces. | Do his shoes that his mom bought him have black and blue laces? | do-insertion, subject-auxiliary inversion |
| I have been baking a lot of cookies for the holidays. | Have I been baking a lot of cookies for the holidays? | subject-auxiliary inversion |
| The neighbor’s dogs had been being walked by someone new. | Had the neighbor’s dogs been being walked by someone new? | subject-auxiliary inversion |
| Your packages could have been being delivered while you were out. | Could your packages have been being delivered while you were out? | subject-auxiliary inversion |
Subject-Verb Inversion
Subject-verb inversion is the movement of a verb phrase functioning as the predicate into the position before the subject. Only the copular be undergoes subject-verb inversion from a declarative sentence to an interrogative sentence. A copular verb is a verb that links the subject complement in the predicate to the grammatical subject. The subject and form of be switch places from declarative to interrogative. For example:
| Declaration | Interrogative |
| I am a teacher. | Am I a teacher? |
| The bread is ready. | Is the bread ready? |
| Your child is a boy. | Is your child a boy? |
| You are an excellent reader. | Are you an excellent reader? |
| We are young. | Are we young? |
| I was a fan of cream cheese sandwiches. | Was I a fan of cream cheese sandwiches? |
| You were top of your class. | Were you top of your class? |
| She was a budding scientist. | Was she a budding scientist? |
| The dog was a dachshund. | Was the dog a dachshund? |
| The books were on the top shelf. | Were the books on the top shelf? |
Do-Insertion and Subject-Auxiliary Inversion
Simple present and simple past verb phrases consist of one verb. All other single-verb predicates require the insertion of the do-operator to form an interrogative. An operator is a word that facilitates the expression of negation, interrogatives, and emphasis in the English language. As the first word in a verb phrase, the do-operator expresses the tense of the verb phrase. The subject and form of be switch places from declarative to interrogative. For example:
| Declaration | Do-Insertion | Interrogative |
| I love cheese. | I do love cheese. | Do I love cheese? |
| That painting belongs in a museum. | That painting does belong in a museum. | Does that painting belong in a museum? |
| My sister knits mittens for charity. | My sister does knit mittens for charity. | Does my sister knit mittens for charity? |
| We read almost every day. | We do read almost every day. | Do we read almost every day? |
| You all bake the best bread. | You all do bake the best bread. | Do you all bake the best bread? |
| I ate already. | I did already eat. | Did I already eat? |
| You broke the fine china. | You did break the fine china. | Did you break the fine china? |
| The dog barked loudly. | The dog did bark loudly. | Did the dog bark loudly? |
| We swam in the lake. | We did swim in the lake. | Did we swim in the lake? |
| The children screamed all night. | The children did scream all night. | Did the children scream all night? |
Subject-Auxiliary Inversion
Subject-auxiliary inversion is the movement of the initial auxiliary verb into the position before the subject. A periphrastic verb phrase is a verb phrase that consists of two or more verbs. The progressive aspect, perfect aspect, perfect-progressive aspect, passive voice, and modal constructions are periphrastic verb phrases. The subject and the first verb of the verb phrase switch places from declarative to interrogative. For example:
| Declaration | Interrogative |
| I am reading a book. | Am I reading a book? |
| You are eating a cookie. | Are you eating a cookie? |
| He has passed the exam. | Has he passed the exam? |
| She had broken her leg. | Had she broken her leg? |
| Rabbits have destroyed my garden. | Have rabbits destroyed my garden? |
| We have been waiting here for hours. | Have we been waiting here for hours? |
| My homework has been turned in already. | Has my homework been turned in already? |
| The furniture had been being stored. | Had the furniture been being stored? |
| I could have been killed. | Could I have been killed? |
| You should have been treated better. | Should you have been treated better? |
English sentences can make statements or ask questions. Interrogative sentences can be formed from declarative sentences through subject-verb inversion, do-insertion and subject-auxiliary inversion, and subject-auxiliary inversion. The process depends on the form of the declarative sentence.
References
Brinton, Laurel J. & Donna M. Brinton. 2010. The linguistic structure of Modern English, 2nd edn. Amsterdam: John Benjamins Publishing Company.
Fromkin, Victoria, Robert Rodman & Nina Hyams. 2006. An introduction to language. Boston: Wadsworth Publishing.
Hopper, Paul J. 1999. A short course in grammar. New York: W. W. Norton & Company.
Huddleston, Rodney. 1984. Introduction to the grammar of English. Cambridge: Cambridge University Press.
