Clauses

B1 · IntermediateSentence Structure & Clauses

She smiled. She smiled, and he waved. Although it was cold, we went outside. Clauses combine to build every kind of sentence.

What you'll learn

An independent clause can stand alone as a complete sentence
A dependent clause cannot stand alone — it needs an independent clause to attach to
A simple sentence has one independent clause; a compound sentence joins two or more with a comma + coordinating conjunction
A complex sentence combines an independent clause with a dependent one; a compound-complex sentence has both patterns together

Independent vs. dependent

Every clause is either independent (it can stand alone as a full sentence) or dependent (it can't — it relies on an independent clause to complete its meaning).

"The train arrived. (independent)"

"Because the train arrived (dependent — incomplete on its own)"

Simple and compound sentences

A simple sentence is just one independent clause. A compound sentence joins two or more independent clauses, usually with a comma plus a coordinating conjunction (and, but, so, or...).

"She left early. (simple)"

"I like tea, and she likes coffee. (compound)"

Complex and compound-complex sentences

A complex sentence combines one independent clause with at least one dependent clause. A compound-complex sentence combines both patterns — two or more independent clauses plus at least one dependent clause.

"When she arrived, everyone cheered. (complex)"

"Although I was tired, I finished the report, and I felt proud. (compound-complex)"

What's covered elsewhere

This lesson introduces the structural classification system itself. The specific coordinating and subordinating conjunctions that join clauses, and specific clause types like relative clauses and noun clauses, each get their own dedicated lessons later.

Real English

"The dog barked, and the cat ran away."

"If it snows, school will close."

"We left early, so we missed the traffic."

"Since you asked, I'll tell you the truth."

Watch out

✗I like tea, she likes coffee.

✓I like tea, and she likes coffee.

Joining two independent clauses with only a comma (no conjunction) is a comma splice — a coordinating conjunction is needed too.

✗Because the train arrived.

✓Because the train arrived, we left the station.

A dependent clause can't stand alone as a complete sentence — it needs an independent clause attached.

✗We left early so, we missed the traffic.

✓We left early, so we missed the traffic.

The comma goes before the coordinating conjunction (so), not after it.

Real life — Explaining a change of plans

"Why did you cancel the trip?"

"Because the weather turned bad, and we didn't want to risk it."

"That makes sense. Although, I was really looking forward to it."

"Me too — we'll reschedule once it clears up."

Practice

Exercise 1 · Identify the sentence type

'I called her, but she didn't answer.' — What kind of sentence is this?

Exercise 2 · Identify the sentence type

'She left early.' — What kind of sentence is this?

Exercise 3 · Identify the sentence type

'Because it rained, we stayed home.' — What kind of sentence is this?

Exercise 4 · Choose the correct compound sentence

Choose the correct compound sentence.

Exercise 5 · Choose the independent clause

Which clause can stand alone as a complete sentence?

Exercise 6 · Choose the sentence with a dependent clause

Choose the sentence with a dependent clause.

Exercise 7 · Choose the correctly punctuated sentence

Choose the correctly punctuated compound sentence.

Exercise 8 · Identify the sentence type

'Although I was tired, I finished the report, and I felt proud.' — What kind of sentence is this?

Exercise 9 · Join into a compound sentence

Join into a compound sentence: 'I wanted to go. I was too tired.'

Exercise 10 · Join into a complex sentence

Join into a complex sentence using 'because': 'We stayed inside. It was raining.'

Exercise 11 · Sort into groups

She smiled.

She smiled, and he waved.

When he waved, she smiled.

The sky is blue.

The sky is blue, but the sea is grey.

Although it was cold, we went outside.

0 / 6 sorted

Quick challenge

Five quick questions to check what stuck.

Question 1 / 5

Score: 0/0

'The dog barked, and the cat ran away.' — What kind of sentence is this?

You learned

An independent clause can stand alone; a dependent clause cannot.
A simple sentence has one independent clause; a compound sentence joins two or more with a comma + coordinating conjunction.
A complex sentence combines an independent clause with a dependent one.
A compound-complex sentence combines both patterns together.

IntermediateSentence Structure & Clauses

Sentence Elements

Learn to identify the building blocks of a clause — Subject, Verb, Object, Complement, and Adverbial.

IntermediateSentence Structure & Clauses

Dummy It

Learn how 'it' works as an empty subject for weather, time, distance, and sentences like 'It's hard to say.'

ElementarySentence Structure & Clauses

Exclamations

Learn the two exclamation patterns — 'What a/an + noun!' and 'How + adjective/adverb!' — for expressing strong feeling.

ElementarySentence Structure & Clauses

Phrases vs Clauses

Learn the basic difference between a phrase (no subject + verb) and a clause (has a subject + verb) — the building blocks of every sentence.