Core Patterns

Subjects & Verbs

Every clause has a subject and a verb, and every diagram in these lessons starts from them. If you find these two parts correctly, every other word in the sentence has a place to attach to.

What you’ll learn

Find the subject and the verb phrase in a statement, a question or a passive sentence
Draw the base line with one full vertical between the subject and the verb
Keep a multi-word verb phrase together in one slot
Identify the subject and the verb phrase in a dependency tree: nsubj or nsubjpass, aux or auxpass, and the root
Correct a missing subject, a subject after the verb, and a verb that agrees with the wrong noun

The base line

You met this picture in Grammar Basics. Draw one horizontal line, the base line. The subject goes on the left and the verb on the right, and a full vertical line separates them. This page adds verbs of more than one word, passives and questions.

The full vertical crosses the base line: it goes above and below it. Do not confuse it with the half vertical, which stops at the base line and comes before a direct object.

Find the verb
Add yesterday and see which word must change: Rain falls → Rain fell yesterday, so falls is the verb. This is the tense test. In a longer verb phrase the first word changes: is whistling → was whistling.
Put who or what before the verb
“What falls?” → Rain. That is the subject. The question works for a passive too: “What had been cleaned?” → the windows.
Draw the line and cut it
Subject left, verb right, full vertical between them.

“Rain falls.”

Reed-Kellogg — the base line and full vertical

nsubj Nominal subject
ROOT Root of the sentence

Dependency — the verb is the root

Comparing the two views

Reed-Kellogg gives the two words equal places, one on each side of the full vertical. The tree does not: falls is the root, and Rain hangs below it as nsubj (nominal subject). In a tree the verb is the centre of the clause. So read a tree from the top: the root is the main verb, and the word its nsubj arrow points to is the subject.

Verb phrases stay together

A verb phrase is the main verb with its helping verbs, the auxiliaries. It can be one word (falls) or several: was whistling, had been cleaned, will have finished. However many words it has, the whole verb phrase fills one slot on the base line, because it does one job.

The dependency tree splits the verb phrase. The main verb, the last one, is the root. Each helping verb hangs from it as aux, or as auxpass when it makes the passive.

In this app a verb phrase is the main verb with its helping verbs, plus not or never when they go with it. Its first verb is a finite verb, and it usually carries the tense. Each clause has one verb phrase, or one per verb when the predicate is compound: He showered and dressed has two.

A verbal is not a verb phrase. In She plans to visit us, plans is the verb phrase and to visit us is an infinitive phrase. Some grammars use verb phrase for the whole predicate; the Roles exercise calls that the Predicate.

“The kettle was whistling.”

Reed-Kellogg — the whole verb phrase in one slot

det Determiner
nsubj Nominal subject
aux Auxiliary
ROOT Root of the sentence

Dependency — the auxiliary is a separate node

Comparing the two views

One slot versus two nodes. Reed-Kellogg writes was whistling as one piece of text, so the diagram cannot tell you that was is the auxiliary. The tree can: was hangs from whistling as aux. But the tree never says that the two words form one verb phrase.

Finding the subject in passives and questions

In a passive sentence the subject does not do the action; it receives it. Compare the active Somebody had cleaned windows with the passive Windows had been cleaned, drawn below. In the passive, Windows is the subject, although somebody else did the cleaning. Diagram it like any other subject. The passive shows only in the verb phrase: a form of be plus a past participle, here been cleaned.

“Windows had been cleaned.”

Reed-Kellogg — a passive subject sits in the ordinary slot

nsubjpass Passive nominal subject
aux Auxiliary
auxpass Passive auxiliary
ROOT Root of the sentence

Dependency — nsubjpass and auxpass name the passive

Comparing the two views

The tree marks the passive and Reed-Kellogg does not. Windows is nsubjpass (passive subject), not nsubj, and been, the helping verb that makes the passive, is auxpass. The other helping verb, had, stays a plain aux: it makes the perfect, not the passive. In the Reed-Kellogg diagram, Windows sits in the ordinary subject slot, and only the verb phrase shows that it is passive.

Most questions put a helping verb in front of the subject, so the subject sits inside the verb phrase: Had the windows been cleaned? To find the subject, turn the question back into a statement. The diagram is drawn in that statement order too, but it keeps the question’s own words.

Rewrite the question as a statement
Had the windows been cleaned? → The windows had been cleaned.
Find the subject in the statement
The subject is the windows, and the verb phrase is had been cleaned.
Diagram it in statement order
Write windows left of the full vertical and Had been cleaned right of it, in one slot, with the on a slant under windows. Keep the words of the question, capital H included: the diagram shows the grammar, not the word order.

Common mistakes with subjects and verbs

Learners often make these three mistakes. The first one comes from Spanish. Each item shows the error (✗) and a correct version (✓).

Keep the subject, and put it before the verb. Spanish can leave the subject out, as in Llegaron tarde, or put it after the verb, as in Llegó el profesor. An English statement needs a subject, and the subject comes before the verb. ✗ Arrived late. ✓ They arrived late. ✗ Arrived the teacher. ✓ The teacher arrived.
Make the verb agree with the subject, not with the nearest noun. ✗ The keys to the classroom is on the desk. ✓ The keys to the classroom are on the desk. The subject is The keys to the classroom, and its main word, keys, is plural. For the -s in she works, see the present tense.
Keep the helping verbs with the main verb. Every helping verb goes right of the full vertical, in the one verb slot. ✗ kettle | was | whistling ✓ kettle | was whistling

Quick check

Find the subject and the verb phrase in Were the children sleeping?
Answer
Turn the question into a statement: The children were sleeping. The subject is the children, and the verb phrase is were sleeping. In the question, the helping verb Were moved in front of the subject, so the subject stands between the two words of the verb phrase. A short answer confirms it: Yes, they were.
Describe the Reed-Kellogg diagram of The tired runners were resting. What goes on the base line, and where do The and tired go?
Answer
The main word of the subject, runners, goes on the base line, left of the full vertical. The verb phrase were resting goes right of it as one unit: the helping verb stays in the verb slot with the main verb. The and tired describe runners, so each hangs on a slant under it.
Choose the verb and explain your choice: The colour of these shoes (is / are) too dark.
Answer
The verb is is. Ask what is too dark: the colour, not the shoes. The subject is The colour of these shoes, and its main word, colour, is singular. The word shoes is inside the phrase of these shoes, which describes colour, so the verb does not agree with it. In the diagram only colour stands on the base line before the full vertical; The and of these shoes hang below it.
In the dependency tree of The cakes were eaten., which word is the root? Which labels do cakes and were get, and why not nsubj and aux?
Answer
The root is eaten, the main verb. The word cakes is nsubjpass and were is auxpass, because the sentence is passive: the cakes did not eat anything; somebody ate them. A form of be plus the past participle eaten makes the passive. The hangs from cakes as det.

Key terms

Subject: The noun, pronoun or noun phrase that the clause is about. It goes left of the full vertical, and the verb agrees with it in number. Rain falls. Leaves fall. The windows had been cleaned. — one word or a whole phrase.
See: Grammar Basics
Predicate: The verb phrase and every word that completes or describes it: everything right of the full vertical. On this page it is mostly the verb phrase alone; later pages add objects and complements. Rain falls. The kettle was whistling on the stove.
See: Grammar Basics
Base line: The long horizontal line of a Reed-Kellogg diagram. It holds the core of the clause: the subject, the verb phrase, and any direct object or complement. Rain falls. — both words stand on it. The kettle was whistling. — kettle and was whistling stand on it; The hangs below.
See: Reed-Kellogg Diagrams
Full vertical: The divider that crosses the base line, above and below it. It separates the subject from the predicate, and each clause has exactly one. Rain falls. — it stands between Rain and falls. Windows had been cleaned. — it stands between Windows and had been cleaned.
See: Reed-Kellogg Diagrams
Verb phrase: The main verb with its helping verbs, plus not or never when they go with it; its first verb is finite. A clause has one, or one per verb when the predicate is compound. It fills one slot on the base line, however many words it has. A verbal is not a verb phrase. The kettle was whistling. — two words, one slot. Windows had been cleaned. — three words, one slot.
See: Modal Auxiliaries · Tense
Finite verb: A verb that can head a clause on its own, usually carrying tense. The non-finite forms cannot, and each gets its own topic later. The kettle whistles. Windows had been cleaned. — had carries the tense; cleaned alone could not head the clause.
See: Grammar Basics · Infinitives · Gerunds · Tense
Voice: Whether the subject acts (active) or is acted on (passive). The passive shows in the verb phrase, as a form of be plus a past participle, and in the dependency labels nsubjpass and auxpass. Somebody had cleaned the windows. — active. The windows had been cleaned. — passive.
See: Sentence Types & Voice · Miscellaneous

Practice on a real sentence

Use the steps on this page: find the verb, then put who or what in front of it. The subject here is a long noun phrase, so include every word that belongs to it. An antagonist is the character who works against the hero. In Roles, choose a role, then drag across the words that play it; in Role match, match the ready-made phrases to their roles. Each correct answer adds its piece to the diagram.

Loading the practice sentence…