Foundations
Sentence Types & Voice
What you’ll learn
- Tell a statement, a question, a command and an exclamation apart
- Find the subject of a question, and the missing subject of a command
- Recognise active and passive voice from the verb phrase
- Read every filter in the Practice Lab and know which page explains it
Four kinds of sentence
A sentence does one of four jobs. It states something, asks something, tells someone to do something, or exclaims. The job is the sentence type, and the end mark usually gives it away — but not always, so it helps to know the other clues.
The ferry leaves at noon. is a statement. Did the ferry leave on time? asks. Shut the window. gives an order. What a long day this was! exclaims. Same words, very different sentences.
Look at the end mark
A question mark means a question; an exclamation mark means an exclamation — unless the sentence is really an order shouted (Sit down!), which is still a command.Look at the word order
A question usually puts an auxiliary or a question word before the subject: Did the ferry leave?, Where does the ferry stop? A statement keeps the subject first.Look for a subject
A command has none on the page — Shut the window. means You shut the window, with the you understood. If the subject is missing and the verb is in its base form, it is a command.
Declarative: a statement
The ordinary sentence. It has a subject, then a verb, and it ends in a full stop. The ferry leaves at noon. and Our neighbours keep bees. are both declarative, and so is every example sentence on most pages of this section.
Diagramming a statement is the base case everything else is measured against: the subject goes left of the vertical, the verb right of it, and the rest hangs off one or the other.
“The ferry leaves at noon.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- prepPrepositional modifier
- pobjObject of preposition
Comparing the two views
nsubj and at as a prep — the same attachment, drawn top-down instead of left-right.Interrogative: a question
A question moves an auxiliary in front of the subject: Did the ferry leave on time?, Has the gate been locked? Or it opens with a question word: Where does the ferry stop? Either way the subject is no longer first, which is what makes questions harder to diagram than they look.
The trick is the one from Subjects & Verbs: turn the question back into a statement in your head, find the subject there, and then diagram the words the sentence actually uses.
Rewrite it as a statement
Did the ferry leave on time? → The ferry did leave on time.Find the subject there
ferry. The auxiliary did belongs with leave, so the verb phrase is did leave.Diagram with the original words
ferry left of the vertical, Did leave right of it, exactly as if the sentence were a statement.
“Did the ferry leave on time?”
- auxAuxiliary
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- prepPrepositional modifier
- pobjObject of preposition
Comparing the two views
aux hanging from leave, and the tree’s shape is the same as the statement’s. Only the word order differs.Imperative: a command
A command leaves its subject out. Shut the window., Wait here. and Please hand me the map. all mean you — the person being spoken to — but none of them says so. Grammarians call this the understood subject.
Reed-Kellogg gives the missing word a placeholder: an x in brackets in the subject slot. The dependency parse does not add words it cannot see, so the tree simply has no subject — the verb is the root and its objects hang from it.
“Shut the window.”
- ROOTRoot of the sentence
- detDeterminer
- dobjDirect object
Comparing the two views
dobj, and there is no nsubj at all — which is exactly how the app knows the sentence is a command.Exclamatory: an exclamation
An exclamation expresses feeling and ends in an exclamation mark: What a long day this was!, How quickly the summer passed! Many begin with what or how, and those two words pull part of the predicate to the front of the sentence.
For diagramming, treat it as the statement it is built on. What a long day this was! is This was a long day with the complement moved forward; the exclamation mark itself changes nothing in either picture.
“What a long day this was!”
- detDeterminer
- amodAdjectival modifier
- attrAttribute
- nsubjNominal subject
- ROOTRoot of the sentence
Active and passive voice
Voice says whether the subject does the action or receives it. In The storm flooded the road. the storm does the flooding — that is the active voice. In The road was flooded by the storm. the road is the subject, but it is on the receiving end — the passive voice.
The passive always shows in the verb phrase: a form of be plus a past participle (was flooded, has been cleaned). The doer, if it is named at all, arrives in a by phrase.
“The storm flooded the road.”
- detDeterminer
- nsubjNominal subject
- ROOTRoot of the sentence
- dobjDirect object
“The road was flooded by the storm.”
- detDeterminer
- nsubjpassPassive nominal subject
- auxpassPassive auxiliary
- ROOTRoot of the sentence
- agentAgent (passive)
- pobjObject of preposition
Comparing the two views
nsubjpass, was is auxpass, and by is labelled agent rather than a plain prep — the tree knows who really did it.What the Practice Lab filters mean
The Practice Lab and the Workbench filter sentences on six things. Each is taught somewhere in this section; this table says where.
| Filter | Values | Explained on |
|---|---|---|
| Type | declarative, interrogative, exclamatory, imperative | this page |
| Structure | simple, compound, complex, compound-complex | Compound-Complex Sentences |
| Voice | active, passive | this page |
| Clause type | relative, noun, adverbial | Adjective Clauses, Noun Clauses, Adverb Clauses |
| Verb type | linking, monotransitive, ditransitive, intransitive | The four verb types |
| Preposition | any preposition the sentence contains | Prepositional Phrases |
Key terms
- Declarative sentence
- A sentence that states something, with the subject before the verb and a full stop at the end. The ferry leaves at noon. Our neighbours keep bees.
- Interrogative sentence
- A question. An auxiliary or a question word comes before the subject, and the sentence ends in a question mark. Did the ferry leave on time? Where does the ferry stop?
See: Subjects & Verbs
- Imperative sentence
- A command or request. The subject you is left unsaid and the verb is in its base form. Shut the window. Please hand me the map.
- Exclamatory sentence
- A sentence that expresses strong feeling and ends in an exclamation mark, often starting with what or how. What a long day this was! How quickly the summer passed!
- Understood subject
- The you a command implies but does not say, written (x) in a Reed-Kellogg diagram. In Wait here. the understood subject is you; in Please hand me the map. it is you again.
- Voice
- Whether the subject performs the action (active) or receives it (passive). Active: The storm flooded the road. Passive: The road was flooded by the storm.