Identify and correct sentence fragments and run-on sentences, use the articles a, an and the, and write simple abbreviations

Learning goal: This lesson teaches three parts of Ohio's 2026 Writing Foundations standard for third grade, first implemented in 2027-28. You will write complete sentences that demonstrate knowledge of conventions: identify and correct sentence fragments and run-on sentences; use the articles a, an and the correctly; and use simple abbreviations, including days of the week, months of the year, titles, units of metric and customary measurement, street names and state names. The first part of the same standard, which is about including a subject and a predicate in every complete sentence, is taught in the companion lesson on legible handwriting and complete sentences.

Part 1: Sentence fragments and run-on sentences

A quick review. A complete sentence has a subject (who or what the sentence is about) and a predicate (what the subject does or is, with a verb), and it tells a complete thought. "Bees buzz." has only two words, and it is complete. A command such as "Close the gate." is complete too, because the subject you is understood. So you cannot identify a fragment or a run-on by counting words. You have to look at the parts.

Identify a fragment. A sentence fragment is a group of words that is written like a sentence, with a capital letter and an end mark, but is missing a part or does not tell a complete thought. Ask three questions.

- Who or what? "Ran across the wet grass." There is no subject. (Ran tells about the past, so this cannot be a command.)
- Does what, or is what? "The gray cat on the porch." There is no predicate.
- Am I left waiting? "When the bell rang." This group has a subject (the bell) and a verb (rang), but the word when makes the reader wait for the rest of the thought. The words because, when, if, after and until often begin this kind of fragment. They do not always make one: "After lunch, we read." is complete, because we read can stand alone.

Correct a fragment. Add the missing part, or join the fragment to a complete sentence beside it: "The puppy ran across the wet grass." "The gray cat on the porch watched the birds." "When the bell rang, we lined up." A group of words that begins with when or because is not wrong in itself. It only needs a complete sentence to hold on to. If it comes first, put a comma after it. If it comes last, you usually need no comma: "We lined up when the bell rang."

Identify a run-on. A run-on sentence is two or more complete sentences that run together without the right punctuation or joining word. Look at "The bell rang we lined up." Find each subject with its predicate: The bell | rang and we | lined up. Those are two complete sentences, and nothing separates them. Putting only a comma between two complete sentences is one kind of run-on: "The bell rang, we lined up." A comma by itself is not strong enough to join two sentences.

A run-on is not simply a long sentence. "After lunch, Maya and her little brother carried the heavy box of library books down the long hall to Room 12." is long, but it has one subject (Maya and her little brother) and one predicate (everything from carried to the end; After lunch only tells when). It is one correct sentence. "I ran he walked." has only four words, and it is a run-on.

Correct a run-on. There are three ways.

1. Make two sentences with a period and a capital letter: "The bell rang. We lined up."
2. Join the two with a comma and a joining word (a conjunction) such as and, but, so or or: "The bell rang, and we lined up."
3. Begin one part with a word such as when or because: "When the bell rang, we lined up."

Choose the way that shows how the two ideas go together.

Part 2: The articles a, an and the

The small words a, an and the are called articles. An article comes before a noun, or before a describing word that is in front of the noun: a dog, a small dog, the dog.

A and an mean "one, and not a special one." Use them with a noun that names one thing: a pencil, an egg. Do not use a or an with a plural noun. A books is wrong; write a book or books. Also do not use a or an with a word for something you measure instead of counting one by one, such as water, sand, milk or rice. A sand is wrong; write sand with no article, some sand or the sand. To talk about one amount of it, name a container or a piece: a cup of water, a bag of rice.

A or an? Listen to the first sound of the next word. Use a before a consonant sound: a bird, a tent, a yellow bus. Use an before a vowel sound: an apple, an egg, an igloo, an owl, an umbrella. The rule is about the sound you hear, not the letter you see.

- An hour and an honest answer: the h is silent, so each word begins with a vowel sound. But a hat and a house: you hear the h.
- A unicorn and a uniform: these words begin with the sound "yoo," and /y/ is a consonant sound. But an umbrella and an uncle begin with a vowel sound.
- The word right after the article decides: an apple but a red apple; a bus but an old bus.

The means "the one that you and your reader both know." Here are three common cases.

- You have already mentioned the thing: "I found a shell and a feather. The shell was pink."
- There is only one: the sun, the moon, the principal of our school.
- Words after the noun point to exactly one: the book on my desk (only one book is there). If there could be several, use a: a tree behind our school.

The works with one thing or many: the dog, the dogs.

When no article is needed. Use no article with a plural noun when you mean those things in general: "Dogs bark." "I like apples." The same is true for a word for something you measure: "Milk is good for you." Most names of people, cities and states take no article: Maya, Dayton, Ohio. Names of rivers and oceans do take the: the Ohio River, the Atlantic Ocean.

Part 3: Simple abbreviations

An abbreviation is a shorter way to write a word. You write Dr. and still say "Doctor." Abbreviations save space in addresses, calendars, charts, labels and notes. In the sentences of a story or report, write most words out (Monday, October, Street, Ohio, inches). Titles before a name are different: Mr., Mrs., Ms. and Dr. are written short everywhere. Writers do not all follow the same conventions for abbreviations, so this lesson says which convention it teaches. Ohio's statement names six groups. Units of measurement are one group with two kinds, customary and metric, so the list below has seven parts.

- Days of the week: a capital letter and a period. Sun., Mon., Tues., Wed., Thurs., Fri., Sat. (You will also see Tue. and Thu.)
- Months of the year: a capital letter and a period. Jan., Feb., Mar., Apr., Aug., Sept., Oct., Nov., Dec. (You will also see Sep.) May, June and July are short already and are usually written in full.
- Titles: a capital letter and a period, used only before a person's name. Mr. Okoro, Mrs. Bell, Ms. Tran, Dr. Reyes. Mr. is short for Mister and Dr. is short for Doctor. Write "Dr. Reyes checked my arm," but "The doctor checked my arm." Miss is a whole word, so it has no period.
- Units of customary measurement: in this lesson, small letters and a period. in. (inch), ft. (foot), yd. (yard), mi. (mile), oz. (ounce), lb. (pound). The letters of oz. and lb. do not match the English words because they come from older words in other languages (lb. is from the Latin word libra). In math and science books you will also see ft, yd and lb with no period. The abbreviation in. keeps its period so that it is not mistaken for the word in.
- Units of metric measurement: small letters and no period, as in mm, cm, m, km, g and kg. The liter is different: it is a capital L, and the milliliter is mL, although some books print a small l.
- Street names: a capital letter and a period, after the name of the street. St. (Street), Ave. (Avenue), Rd. (Road), Dr. (Drive), Ln. (Lane), Blvd. (Boulevard). Notice Dr.: before a person's name it means Doctor, and after a street's name it means Drive. (Printed mailing labels sometimes show street words in capital letters with no period; this lesson uses the form with a period.)
- State names: in a mailing address, this lesson uses the two-letter postal abbreviation, which is two capital letters and no period: OH for Ohio, and for Ohio's five neighbors MI (Michigan), IN (Indiana), KY (Kentucky), WV (West Virginia) and PA (Pennsylvania). Older abbreviations with periods, such as Mich., Ind., Ky. and Pa., are found in older books. In a sentence, write the state name in full.

One or many. For every unit, the abbreviation is the same for one or for many: 1 in. and 6 in. (not ins.), 1 cm and 30 cm (not cms). On signs and packages you may see lbs., but in this lesson write lb. for one pound or for many.

One period is enough. If an abbreviation with a period ends a sentence in a note, do not add a second period: "Meet us at 42 Elm St."

A worked model inside the lesson. Leo writes a reminder card for the class calendar. The card, the trip and the distance are invented for this lesson. The heading reads Thurs, Oct 9 and the card says: "Our class is visiting a Ohio River. The bus leaves at 8:00 we will walk 1 mi to the dock. Because it might rain. Bring a umbrella."

Leo checks three things. Abbreviations: the day, the month and the customary unit each need a period, so the heading becomes Thurs., Oct. 9 and the distance becomes 1 mi. A card is a short note, so abbreviations fit here. Articles: there is only one Ohio River, and a river's name takes the: the Ohio River. Umbrella begins with a vowel sound: an umbrella. Sentences: "The bus leaves at 8:00 we will walk 1 mi. to the dock." holds two complete sentences (The bus | leaves at 8:00 and we | will walk 1 mi. to the dock) with nothing between them, so it is a run-on. "Because it might rain." leaves the reader waiting, so it is a fragment. Leo joins it to the command that follows.

The corrected card: "Our class is visiting the Ohio River. The bus leaves at 8:00. We will walk 1 mi. to the dock. Because it might rain, bring an umbrella."

Worked example 1 — Identify and correct fragments. Test three groups of words. (a) "Jumped over the puddle." Who or what? Nobody is named, so the subject is missing. Corrected: "My sister jumped over the puddle." (b) "My cousin from Toledo." Does what, or is what? Nothing is said about the cousin, so the predicate is missing. Corrected: "My cousin from Toledo plays the drums." (c) "Because the paint was still wet." It has a subject (the paint) and a verb (was), but because leaves the reader waiting. Corrected: "Because the paint was still wet, we waited." or "We waited because the paint was still wet."

Worked example 2 — Identify and correct a run-on. "The paint was wet, we could not hang the pictures." Find each subject and predicate: The paint | was wet and we | could not hang the pictures. Two complete sentences are joined by only a comma, so this is a run-on. Three corrections: "The paint was wet. We could not hang the pictures." "The paint was wet, so we could not hang the pictures." "Because the paint was wet, we could not hang the pictures." Now test a long sentence: "On Friday morning, our art teacher and two helpers from the fifth grade hung all twenty pictures in the front hall." It has one subject (our art teacher and two helpers from the fifth grade) and one predicate (hung all twenty pictures in the front hall); On Friday morning only tells when. It is long, and it is not a run-on.

Worked example 3 — A or an: listen to the sound. Say each word aloud. Hour begins with a vowel sound because the h is silent: an hour. Horse begins with the sound /h/: a horse. Uniform begins with "yoo": a uniform. Umpire begins with a vowel sound: an umpire. Orange begins with a vowel sound: an orange. In ripe orange, the next word after the article is ripe, which begins with /r/: a ripe orange.

Worked example 4 — A, an or the. "We saw ___ owl in ___ tree behind our school. ___ owl turned its head and looked at ___ moon." The owl is new to the reader and owl begins with a vowel sound: an owl. The tree is new too, and it is one of many trees: a tree. In the second sentence the owl has already been mentioned, so the reader knows which one: The owl. There is only one moon: the moon.

Worked example 5 — Abbreviate an address and a date. For an envelope, "Doctor Lena Park, 45 Oak Road, Dayton, Ohio" becomes three lines: Dr. Lena Park / 45 Oak Rd. / Dayton, OH. The title and the street name each get a capital letter and a period. The state gets its postal abbreviation, two capital letters with no period. (The person and the address are invented, and a real envelope also needs a ZIP code after the state.) On a calendar, "Wednesday, February 11" becomes Wed., Feb. 11.

Worked example 6 — Abbreviate units of measurement. A garden chart lists: bean plant, 9 inches tall; row, 3 feet long; seed packet, 25 grams; path, 4 meters long; watering can, 2 liters. With abbreviations, the chart shows 9 in., 3 ft., 25 g, 4 m and 2 L in that order. The two customary units have a period in this lesson. The three metric units have none. No s is added for more than one.

Record: three-part editing chart. Fold a page into three parts. In part 1, write the three fragment questions (Who or what? Does what, or is what? Am I left waiting?) and the three ways to correct a run-on, each with an example of your own. In part 2, write a, an, the and no article, each with its rule and two examples of your own. In part 3, list the six groups of abbreviations from this lesson and, beside each group, copy one example that you find on a calendar, a ruler, a map or an envelope.

Editing practice. Copy and correct this paragraph: "Our class planted a garden on a Friday in May. The soil in our garden was dry. We filled an watering can it held 2 gallons. Mrs Chen showed us a earthworm, it wiggled back into a soil. After we watered the beans." Look for one fragment, two run-ons, three article mistakes and one abbreviation mistake. Then tell a partner how you corrected each one.

Independent performance. Make a reminder card for a real or made-up class event, and write a paragraph about the event. The card has a heading with an abbreviated day and date, a name and address that use a title, a street name and a state abbreviation, and a short list of things to bring with two measurements, one customary and one metric, written with abbreviations. The paragraph has at least five sentences and writes its words out in full, except for a title before a name. Success criteria: (1) every sentence in the paragraph has a subject and a predicate and tells a complete thought; (2) a partner finds no fragments and no run-ons, and I can point to a place where I joined two ideas with a comma and a joining word or with when or because; (3) I chose a or an by the first sound of the next word; (4) I used the where the reader knows which one I mean; (5) on the card, the abbreviated day, month, title, street name and customary unit each have a period, and the metric unit and the postal state abbreviation do not (May, June, July and Miss have no period either); (6) no abbreviation at the end of a sentence has two periods.