TEAS English: Sentence Structure, Clause Types, and Sentence Formation Guide

Sentence structure questions make up a significant portion of the TEAS English and Language Usage section. These questions test whether you can identify correctly formed sentences, spot errors like fragments and run-ons, and understand how clauses combine to create meaning. The good news is that sentence structure follows clear, learnable rules — once you know them, these become some of the easiest points to earn.

This guide breaks down everything you need to know about sentence structure for the TEAS: the building blocks of sentences, the four sentence types, how to identify and fix common errors, and practice strategies to make these concepts automatic by test day.

The Building Blocks: Subjects, Predicates, and Clauses

Every sentence is built from the same fundamental parts. A subject is who or what the sentence is about. A predicate is what the subject does or is — it always contains a verb. Together, a subject and a predicate form a clause. Understanding clauses is the key to understanding all sentence structure.

• Subject: The noun or pronoun performing the action. In 'The nurse administered the medication,' the subject is 'The nurse.'
• Predicate: The verb and everything that follows it. In the same sentence, the predicate is 'administered the medication.'
• Phrase: A group of words that adds information but does NOT contain both a subject and a verb acting together. Example: 'in the morning' or 'running quickly.'
• Clause: A group of words that DOES contain both a subject and a verb. Clauses are either independent or dependent.

Independent vs. Dependent Clauses

This distinction is the single most important concept for TEAS sentence structure questions. An independent clause can stand alone as a complete sentence — it expresses a complete thought. A dependent clause cannot stand alone because it begins with a subordinating word that makes it incomplete.

• Independent clause: 'The patient recovered quickly.' — Complete thought, can be a sentence on its own.
• Dependent clause: 'Because the patient recovered quickly' — Has a subject and verb but is incomplete due to 'because.' Your brain wants to know: what happened because the patient recovered?
• Dependent clause: 'When the doctor arrived' — Incomplete. What happened when the doctor arrived?
• Dependent clause: 'Although the treatment was expensive' — Incomplete. What is the contrast being set up?

The Four Sentence Types

Every grammatically correct sentence falls into one of four structural types. The TEAS may ask you to identify sentence types directly, or it may test your understanding indirectly by asking you to fix a structural error.

Simple Sentence: Contains exactly one independent clause and no dependent clauses. It can have compound subjects or compound predicates, but there is only one main clause. Examples:

• 'The nurse checked the patient's vitals.' (one subject, one predicate)
• 'The nurse and the doctor reviewed the chart.' (compound subject, still one clause)
• 'The nurse checked the vitals and recorded the results.' (compound predicate, still one clause)

Compound Sentence: Contains two or more independent clauses joined by a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so) or a semicolon. Each clause could stand alone as its own sentence.

• 'The patient felt better, so the doctor discharged her.' (two independent clauses joined by 'so')
• 'The lab results were normal; the patient was relieved.' (two independent clauses joined by a semicolon)
• 'The medication was effective, but it caused drowsiness.' (two independent clauses joined by 'but')

Complex Sentence: Contains one independent clause and at least one dependent clause. The dependent clause can come before or after the independent clause.

• 'Because the patient had a fever, the nurse administered acetaminophen.' (dependent clause first, comma, then independent clause)
• 'The nurse administered acetaminophen because the patient had a fever.' (independent clause first, no comma needed before 'because')
• 'When the results came back, the team revised the treatment plan.' (dependent clause first)

Compound-Complex Sentence: Contains two or more independent clauses AND at least one dependent clause. These are the most complex structures and appear less frequently on the TEAS, but you should be able to recognize them.

• 'Although the surgery was risky, the surgeon proceeded carefully, and the patient made a full recovery.' (one dependent clause + two independent clauses)
• 'When the ambulance arrived, the paramedics stabilized the patient, and they transported her to the hospital.' (one dependent + two independent)

Coordinating vs. Subordinating Conjunctions

Conjunctions are the glue that connects clauses, and knowing which type you are looking at tells you immediately what sentence structure is being created.

• Coordinating conjunctions (FANBOYS): for, and, nor, but, or, yet, so — These join elements of equal grammatical rank. When joining two independent clauses, place a comma before the conjunction.
• Subordinating conjunctions: because, although, when, while, if, since, before, after, unless, until, whereas — These create dependent clauses by making one clause subordinate (less important) to another.
• Conjunctive adverbs: however, therefore, moreover, nevertheless, consequently, furthermore — These connect independent clauses but require a semicolon before them and a comma after. Example: 'The treatment was effective; however, it had side effects.'

Sentence Fragments: The Most Common Error

A sentence fragment is a group of words that is punctuated like a sentence but is not a complete sentence. Fragments typically fall into three categories on the TEAS:

• Missing subject: 'Ran the tests and recorded the data.' — Who ran the tests? No subject is present.
• Missing verb (or has only a verbal): 'The nurse checking the patient's blood pressure.' — 'Checking' is a participle, not a complete verb. It should be 'was checking' or 'checked.'
• Dependent clause standing alone: 'Because the medication was out of stock.' — This has a subject and verb but is incomplete due to 'because.' It needs an independent clause to complete the thought.

To fix a fragment, either add the missing element (subject, verb, or independent clause) or remove the subordinating conjunction that is making a clause dependent. The TEAS will typically give you four options and ask which one correctly completes or fixes the sentence.

Run-On Sentences and Comma Splices

A run-on sentence occurs when two independent clauses are joined without proper punctuation or a conjunction. A comma splice is a specific type of run-on where two independent clauses are connected with just a comma and no conjunction.

• Run-on: 'The patient felt dizzy the nurse called the doctor.' — Two complete sentences smashed together with nothing between them.
• Comma splice: 'The patient felt dizzy, the nurse called the doctor.' — A comma alone cannot join two independent clauses.
• Fix 1 — Period: 'The patient felt dizzy. The nurse called the doctor.'
• Fix 2 — Semicolon: 'The patient felt dizzy; the nurse called the doctor.'
• Fix 3 — Comma + conjunction: 'The patient felt dizzy, so the nurse called the doctor.'
• Fix 4 — Subordination: 'Because the patient felt dizzy, the nurse called the doctor.'

Subject-Verb Agreement in Complex Sentences

When sentences get longer and more complex, subject-verb agreement errors become harder to spot — which is exactly why the TEAS tests them. The trick is to identify the true subject and ignore everything between it and the verb.

• 'The box of medical supplies was delivered.' — The subject is 'box' (singular), not 'supplies.' The verb 'was' is correct.
• 'The results of the blood test indicate an infection.' — The subject is 'results' (plural), not 'test.' The verb 'indicate' is correct.
• 'Each of the patients has been evaluated.' — 'Each' is always singular, so 'has' is correct even though 'patients' is plural.
• 'Neither the doctor nor the nurses were available.' — With 'neither...nor,' the verb agrees with the nearer subject ('nurses' = plural = 'were').

Parallel Structure

Parallel structure means that items in a list or elements joined by a conjunction should follow the same grammatical pattern. This is tested frequently on the TEAS and is one of the easier concepts to master once you know what to look for.

• Not parallel: 'The nurse enjoys reading, running, and to cook.' — Two gerunds and one infinitive.
• Parallel: 'The nurse enjoys reading, running, and cooking.' — All gerunds.
• Not parallel: 'The treatment plan includes medication, therapy, and changing the diet.' — Two nouns and one gerund phrase.
• Parallel: 'The treatment plan includes medication, therapy, and dietary changes.' — All nouns.
• Not parallel: 'She was both intelligent and had compassion.' — Adjective and verb phrase.
• Parallel: 'She was both intelligent and compassionate.' — Both adjectives.

Strategies for Sentence Structure Questions on Test Day

When you encounter a sentence structure question on the TEAS, follow this systematic approach:

• Step 1: Read the sentence and identify all the clauses. Count the subjects and verbs to determine how many clauses exist.
• Step 2: Classify each clause as independent or dependent. Look for subordinating conjunctions that signal dependent clauses.
• Step 3: Check the connections between clauses. Are independent clauses properly joined with a conjunction, semicolon, or period? Is there a comma splice or run-on?
• Step 4: Verify subject-verb agreement by mentally crossing out prepositional phrases and other modifiers between the subject and verb.
• Step 5: If the question asks you to choose the best revision, eliminate options that create new errors (fragments, run-ons, or agreement problems).

Quick Reference: Sentence Structure Rules

Keep these rules at your fingertips during your final review before the test:

• Every sentence must have at least one independent clause with a subject and a verb.
• A comma plus a coordinating conjunction (FANBOYS) joins two independent clauses.
• A semicolon joins two independent clauses without a conjunction.
• A comma alone CANNOT join two independent clauses — that is a comma splice.
• When a dependent clause comes first, follow it with a comma before the independent clause.
• When the independent clause comes first, no comma is usually needed before the dependent clause.
• Fragments are fixed by adding the missing subject, verb, or independent clause.
• Items in a list must follow parallel grammatical structure.
• The verb must agree with the subject, not with words between them.

Sentence structure is one of the most predictable and learnable areas of the TEAS English section. Every question follows the same grammatical rules, and once you can quickly identify clause types and their connections, you will spot errors almost instantly. Practice with real questions, review the mistakes you make, and these concepts will become second nature by test day.