Improve sentence structure in a piece of writing - TACHS Written Expression

SECTION 1

Why Sentence Structure Matters

People have cared about clear writing for thousands of years. In ancient Greece and Rome, students studied rhetoric (the art of using words effectively). They practiced arranging their sentences so listeners could follow every idea. Over time, teachers figured out patterns that make writing easier to read and more powerful.

On the TACHS exam, you will see passages where some sentences are awkward, choppy, or confusing. Your job is to pick the best revision. Understanding how sentence structure has been taught over the centuries helps you see why certain patterns work better than others.

~400 BC • Ancient Greek Rhetoric

Aristotle taught students to arrange words for clarity and persuasion. He showed that the order of ideas in a sentence changes how people feel about them.

1700s • Grammar Rules Take Shape

English grammar books became popular. Writers like Samuel Johnson created dictionaries and guides that set standards for clear sentences.

1918 • Strunk's Elements of Style

William Strunk Jr. published a tiny book of writing rules. His advice—"omit needless words"—is still taught in schools today.

Today • Standardized Tests & Clear Writing

Exams like the TACHS test whether you can spot and fix sentence problems. Strong sentence structure is a skill every student needs.

The big question is: what makes one sentence better than another? That is exactly what this lesson will help you answer.

SECTION 2

Core Principles of Strong Sentence Structure

Good sentences share a few important traits. When you learn these traits, you can fix almost any weak sentence you find on the TACHS or in your own writing.

Clarity

A clear sentence says exactly what you mean. The reader should never have to guess your point. Put the subject (who or what) and verb (action) close together.

Variety

Mix short and long sentences. If every sentence sounds the same, your writing becomes boring. Changing the rhythm keeps readers interested.

Conciseness

Cut words you don't need. "Due to the fact that" can become "because." Shorter sentences are usually stronger.

Correct Combining

Use conjunctions (and, but, so) or subordinators (because, although, when) to join related ideas smoothly.

Parallel Structure

Items in a list or comparison should follow the same grammatical pattern. "She likes running, swimming, and biking" is parallel. "She likes running, to swim, and bikes" is not.

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KEY TAKEAWAY

Think of a sentence like a path through a park. A clear, smooth path helps people walk quickly and enjoy the scenery. A path full of twists, dead ends, and potholes makes the trip frustrating. Your goal is to build smooth paths for your readers.

SECTION 3

Seeing Sentence Types

Before you can improve a sentence, you need to know the four main sentence types. The diagram below shows how each type is built from independent clauses (complete thoughts that can stand alone) and dependent clauses (groups of words that need an independent clause to make sense).

The four sentence types differ by how many independent clauses and dependent clauses they contain. Good writers use all four types to create variety.

Notice how each type adds more parts. A simple sentence has just one independent clause. A compound sentence links two independent clauses with a conjunction. A complex sentence pairs an independent clause with a dependent one. Mixing these types keeps your writing lively.

SECTION 4

How Sentence Problems Happen

Most sentence-structure errors fall into a few common categories. Once you learn to spot them, fixing them becomes much easier. Let's look at the four biggest problems you will meet on the TACHS.

Run-On Sentences

A run-on sentence happens when two complete thoughts are joined without the right punctuation or a conjunction. For example: I love pizza I eat it every Friday. Those are two separate ideas crammed together. You can fix a run-on by adding a period, a semicolon, or a comma plus a conjunction.

Sentence Fragments

A sentence fragment is a group of words that looks like a sentence but is missing a subject, a verb, or a complete thought. Running down the street. Who is running? We don't know. To fix it, add the missing piece: Maria was running down the street.

Choppy Sentences

Sometimes every sentence in a paragraph is very short. It rained. We stayed inside. We played games. Each sentence is correct, but together they sound robotic. Combining them creates a smoother flow: Because it rained, we stayed inside and played games.

Wordy Sentences

A wordy sentence uses more words than it needs. At this point in time, I am of the opinion that we should leave. That's 16 words. The cleaner version is: I think we should leave now. Only 7 words, and the meaning is the same.

Use this flowchart to diagnose sentence problems. Start at the top and follow the arrows based on what you find.

SECTION 5

Techniques for Improving Sentences

Now that you can spot problems, let's learn specific techniques to fix them. These are the exact skills the TACHS tests.

Technique	Before (Weak)	After (Strong)
Combine choppy sentences	The sky was dark. The wind blew hard. We went inside.	Because the sky was dark and the wind blew hard, we went inside.
Fix a run-on	She studied all night she passed the test.	She studied all night, so she passed the test.
Complete a fragment	Running through the park on a sunny day.	Liam was running through the park on a sunny day.
Cut wordiness	In my personal opinion, I believe that dogs are the best pets.	I believe dogs are the best pets.
Use parallel structure	She likes to hike, swimming, and she rides bikes.	She likes hiking, swimming, and biking.

Five common techniques for improving sentence structure

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TACHS Tip

On the TACHS, read each answer choice aloud in your head. The best answer usually sounds natural, is not too long, and fixes the original problem without creating a new one.

SECTION 6

Worked Example: Revising a Paragraph

Let's walk through revising a short paragraph step by step, just like you would on the TACHS.

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ORIGINAL PARAGRAPH

Volcanoes are dangerous. They erupt. Lava flows down the sides. Many people have been killed by volcanoes throughout the course of history there are over 1,500 active volcanoes in the world today.

Revising Step by Step

1
Step 1 — Find the Problems

Read the paragraph carefully. The first three sentences are very short and choppy. The last sentence is a run-on because two complete thoughts are jammed together without punctuation. The phrase "throughout the course of history" is wordy.

Problems found: choppy sentences, one run-on, wordiness.
2
Step 2 — Combine Choppy Sentences

The first three sentences all talk about how volcanoes are dangerous. Combine them: Volcanoes are dangerous because they erupt and send lava flowing down their sides.

Three choppy sentences → one smooth complex sentence.
3
Step 3 — Fix the Run-On

Split the run-on into two sentences or add a conjunction. We can use a semicolon: Many people have been killed by volcanoes throughout history; over 1,500 active volcanoes exist in the world today.

Run-on fixed with a semicolon.
4
Step 4 — Cut Wordiness

We already trimmed "throughout the course of history" to "throughout history" in the previous step. Always look for extra words you can remove.

Wordy phrase shortened by 3 words.
5
Step 5 — Read the Revised Paragraph

Here is the final version: Volcanoes are dangerous because they erupt and send lava flowing down their sides. Many people have been killed by volcanoes throughout history; over 1,500 active volcanoes exist in the world today. This version is clearer, smoother, and more interesting to read.

Revised paragraph: 2 sentences instead of 5, no errors, clear and concise.

SECTION 7

Strengths & Limitations of Revision Strategies

Not every strategy works in every situation. Here is a quick comparison so you can choose the right tool.

Strategy	Strengths	Watch Out For
Combining sentences	Removes choppiness; shows how ideas connect.	Don't combine too many ideas into one sentence or it becomes hard to follow.
Splitting run-ons	Each idea gets its own clear sentence.	Splitting too much can bring back choppiness.
Cutting wordiness	Makes writing punchy and direct.	Don't cut so much that you lose important details.
Fixing parallel structure	Lists and comparisons sound balanced and polished.	Only applies when a sentence has a list or paired items.

Comparison of revision strategies

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KEY TAKEAWAY

Think of revision strategies like tools in a toolbox. A hammer is great for nails, but you wouldn't use it to tighten a screw. Match the strategy to the problem — diagnose first, then pick the right fix.

SECTION 8

Connecting to Stronger Writing Skills

Improving sentence structure is a stepping stone to bigger writing skills. Once you master sentences, you can work on organizing whole paragraphs, writing persuasive essays, and developing your own writing voice.

Skill Level	What You Focus On
Beginner	Fix fragments, run-ons, and subject-verb agreement.
Intermediate (you are here!)	Combine sentences, cut wordiness, use variety and parallel structure.
Advanced	Use rhetorical techniques—repetition for emphasis, short sentences for drama, complex sentences for nuance.
Expert	Develop a personal voice and style. Control sentence rhythm to match tone and audience.

Writing skill progression

In high school, you will study more advanced sentence techniques like using appositives (renaming phrases), participial phrases (phrases starting with -ing or -ed words), and periodic sentences (sentences that save the main point for the end). The skills you learn now are the foundation for all of that.

SECTION 9

Practice Problems

Try these five problems on your own. They go from easier to harder, just like the TACHS. After each question, check the answer to see if you got it right.

Question 1: CONCEPTUAL

Which of the following is a sentence fragment? (A) The cat slept on the mat. (B) Running through the field of flowers. (C) We went to the store, and we bought milk. (D) Because it was raining, she took an umbrella.

Show answer

The answer is (B). "Running through the field of flowers" is a fragment because it has no subject and no main verb. We don't know who is running. Choices A, C, and D are all complete sentences with subjects and verbs. On the TACHS, look for groups of words that are missing a subject or a complete verb—those are fragments.

Question 2: BASIC CALCULATION

Read this run-on sentence and choose the best revision. "The movie was exciting it kept us on the edge of our seats." (A) The movie was exciting, it kept us on the edge of our seats. (B) The movie was exciting; it kept us on the edge of our seats. (C) The movie was exciting it, kept us on the edge of our seats. (D) The movie was exciting and it and kept us on the edge of our seats.

Show answer

The answer is (B). A semicolon correctly joins two related independent clauses. Choice A creates a comma splice (a type of run-on). Choice C puts the comma in the wrong place. Choice D has an awkward extra "and." When two complete thoughts are closely related, a semicolon is a clean fix.

Question 3: INTERMEDIATE

Combine these three choppy sentences into one smooth sentence: "The park was crowded. Kids were playing on the swings. Parents were sitting on benches." Write your combined sentence.

Show answer

A strong revision might be: "The park was crowded with kids playing on the swings and parents sitting on benches." This combines all three ideas into one sentence. The word "with" introduces the details, and the parallel phrases "kids playing" and "parents sitting" create a balanced structure. You could also write: "In the crowded park, kids played on the swings while parents sat on benches." Both versions work because they eliminate choppiness while keeping all the information.

Question 4: APPLIED

Read the paragraph below and identify two sentence-structure problems. Then rewrite the paragraph to fix them. "Our school fundraiser was a big success we raised over $2,000. Selling baked goods and holding a raffle. The money will be used for new library books."

Show answer

The two problems are: (1) a run-on between "success" and "we raised," and (2) a fragment in "Selling baked goods and holding a raffle" (no subject or main verb). A good revision: "Our school fundraiser was a big success; we raised over $2,000 by selling baked goods and holding a raffle. The money will be used for new library books." The semicolon fixes the run-on, and attaching the fragment to the first sentence gives it a subject and verb. The final sentence was already correct.

Question 5: CRITICAL THINKING

A classmate writes: "I enjoy playing soccer and to read books and also I like cooking food for my family on the weekends." This sentence has two problems. Name them both and write a revised version that fixes everything.

Show answer

The two problems are: (1) faulty parallel structure—"playing," "to read," and "cooking" are in three different forms, and (2) wordiness—"also I like" is unnecessary when the items are already in a list. A revised sentence: "I enjoy playing soccer, reading books, and cooking for my family on the weekends." Now all three items use the -ing form (playing, reading, cooking), which is parallel. The wordy phrase is gone, and the sentence is shorter and easier to read. This shows how fixing parallel structure and cutting wordiness can work together to make a sentence much stronger.

SUMMARY

Lesson Summary

Summary

Improving sentence structure means spotting and fixing common problems like fragments, run-on sentences, choppy writing, and wordiness. You fix these problems by combining sentences with conjunctions or subordinators, splitting run-ons with proper punctuation, cutting unnecessary words, and using parallel structure in lists and comparisons.

Strong writers use a mix of simple, compound, complex, and compound-complex sentences to create variety and keep readers engaged. On the TACHS, always read answer choices carefully, look for the one that sounds natural, and make sure the revision does not introduce a new error. Diagnose first, then fix—just like following a flowchart. These skills will help you not only on the test but in every essay and report you write.