Simple Sentences

One complete thought with a subject and a predicate

Learn how to recognize, write, and improve simple sentences. Practice with activities and download a ready-to-print worksheet.

Lesson Objectives

Identify

Find the subject and predicate in simple sentences.

Write

Create clear, correct simple sentences.

Fix

Correct fragments and run-ons into simple sentences.

Expand

Use compound subjects or verbs to add detail.

What is a Simple Sentence?

One independent clause (subject + predicate) expressing a complete thought.

  • Must have a subject (who/what) and a predicate (verb + the rest).
  • Can be short or long, as long as the thought is complete.
  • No dependent clause markers like because, although, if.

💡 Quick Test: If you can put "It is true that..." in front and it makes sense, you probably have a simple sentence!

SimpleBirds fly.
SimpleMy friend cooks dinner every night.

⚠️ Watch out: Don't confuse length with complexity. "The very tired students" is still one simple subject!

Subject and Predicate

  • Subject: who or what the sentence is about.
  • Predicate: what the subject does or is.
SubjectThe teacher | explains the lesson.
PredicateThe teacher | explains the lesson.

Tip: Find the verb first, then ask "Who/What + verb?"

💡 Memory Aid: Subject = doer, Predicate = what they do/are

Identifying the Subject

Example My dog barks.
Example The red bus stopped suddenly.

Note: Modifiers can come with the subject (the red bus), but the simple subject is the main noun (bus).

🔍 Pro Tip: Cross out prepositional phrases first—they usually aren't the subject!

Identifying the Predicate

ExampleThe baby slept peacefully.
ExampleOur neighbors are planting trees today.

📝 Remember: The predicate includes the verb + everything that comes after it (objects, complements, modifiers).

Common Simple Sentence Patterns

SV

Birds fly.

Rain falls.

SSV

Ken and Ana study.

My parents and I cooked.

SVV

She sings and dances.

They laughed and clapped.

SSVV

Ken and Ana read and write.

Mom and Dad shop and cook.

Remember: Even with compound parts, it’s still one independent clause → still a simple sentence.

What a Simple Sentence is NOT

  • Not compound (two independent clauses joined by a coordinator).
  • Not complex (one independent + at least one dependent clause).
  • Watch for words like because, although, when, if → these start dependent clauses.
SimpleThe sun set quickly.
Not SimpleThe sun set, and the stars appeared. (compound)

Fragments vs Simple Sentences

  • Fragment: lacks a subject, a verb, or a complete thought.
  • Simple sentence: has both subject and predicate → complete thought.
FragmentBecause the bus was late.
SimpleThe bus was late.

⚠️ Common Fragment Trap: Starting with "Because," "Although," "When," or "If" usually creates a fragment—you need more!

Run-ons vs Simple Sentences

  • Run-on: two independent clauses incorrectly joined.
  • Fix by adding a period, a semicolon, or a comma + coordinator (and, but, or, so, for, nor, yet).
Run-onI finished my homework I watched TV.
FixI finished my homework. I watched TV.

🚨 Red Flag: If you can insert "and" between two parts and both sides still make complete sense, you might have a run-on!

Punctuation in Simple Sentences

  • End punctuation: period (.), question mark (?), exclamation (!)
  • Use a comma to separate items in a series within a simple sentence.
  • Do not use a comma between the subject and the verb.

✋ Stop! Never put a comma between the subject and verb: "The students, walked" is wrong!

Combine for Clarity

Combine two short ideas into one simple sentence using a compound subject or verb.

BeforeKen reads. Ana reads.
AfterKen and Ana read.

Common Mistakes

Fragments

WrongBecause I was tired.
RightI went to bed early because I was tired.

Comma splice

WrongI studied, I passed.
RightI studied, so I passed.

💪 Quick Fix Strategy: Read your sentence out loud—if you naturally pause but there's no punctuation, you might need to fix it!

Guided Practice

Identify subject and predicate; decide if it’s a fragment or a simple sentence.

SubjectMy sister sings beautifully.
PredicateThe students are waiting outside.
Fragment?After the rain stopped. → Fragment

Practice: Choose the Best Answer

Question:

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Tip: Check for a subject and a complete predicate.

Score: 0

Activity: Subject Hunt

Click all the words that make up the subject.

In the quiet library , the students studied .

Hint: The subject is who/what the sentence is about. In this sentence, it’s just before the verb.

🎯 Hunt Strategy: Look for WHO or WHAT the sentence talks about. Skip descriptive words at the beginning!

Activity: Predicate Hunt

Click all the words that make up the predicate.

My dog barked loudly at night .

🔍 Predicate Detective: Find the action word (verb) first, then grab everything that tells us about that action!

Activity: Fragment or Simple Sentence?

Choose F (fragment) or S (simple sentence).

  • When the power returned.
  • The lights turned on.
  • Because the rain stopped.
  • We left the shelter.

⚠️ Fragment Alert: If it starts with "When," "Because," or "After," it's probably incomplete—what happened next?

Activity: Build a Simple Sentence

Choose a subject and a predicate to make a complete simple sentence.

  • +

🔧 Builder Tip: Pick the subject first (who does it), then choose the predicate that makes sense together!

Quick Check

IdentifySubject? Predicate? "The baby slept peacefully."
AnswerSubject = The baby; Predicate = slept peacefully

📝 Quick Test: Cover "The baby"—does "slept peacefully" make sense alone? No! So "The baby" is the subject.

Practice Booster

Keep going to build confidence.

Question:

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💪 Confidence Builder: Don't worry about speed—focus on getting the logic right first!

Score: 0

Assessment

How to take this: Choose the best answer for each question, then click Check Answers.

🎯 Assessment Strategy: Read each sentence twice—once for meaning, once to check for subject and predicate!

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Open Printable Worksheet

Key Takeaways

Simple sentence = one independent clause.
Must have subject + predicate, complete thought.
Use compound subjects/verbs to add variety.
Avoid fragments and run-ons.

🏆 Master Tip: When writing, ask yourself: "Who did what?" If you can answer both, you probably have a simple sentence!

Nice Work!

You completed the Simple Sentences lesson

Press R to reset or F for fullscreen when presenting.

Next Steps

  • Retake the assessment
  • Fix fragments in your writing
  • Write 5 simple sentences using different patterns

🌟 Keep Growing: Simple sentences are the foundation—master these and complex writing becomes much easier!