1.3 | Sentence Structures

šŸ§  What Is a Sentence?

At its core, a sentence must have:

  • A subject (who or what it's about)

  • A predicate (what the subject does or is)

  • It must express a complete thought

šŸ§© The Four Sentence Structures:

1. Simple Sentence

One independent clause. One complete idea.
Formula: Independent Clause

  • She writes.

  • The sky glows pink at sunset.

āœ… It may contain compound elements (multiple subjects or verbs):

Tom and Lily play and laugh.

2. Compound Sentence

Two or more independent clauses joined by a conjunction or semicolon.
Formula: Independent Clause + (FANBOYS or ;) + Independent Clause

  • I love literature, and I study it daily.

  • He tried to sleep; the thunder kept him awake.

FANBOYS = For, And, Nor, But, Or, Yet, So

3. Complex Sentence

One independent clause + one or more dependent clauses.
Formula: Dependent Clause + Independent Clause
ā€”orā€”
Independent Clause + Dependent Clause

  • Because she reads often, her vocabulary is strong.

  • Her vocabulary is strong because she reads often.

Dependent clauses often begin with subordinating conjunctions like:
Although, Since, When, Because, While, If, Until, Unless, After

4. Compound-Complex Sentence

At least two independent clauses + at least one dependent clause
Formula: Dependent Clause + Independent Clause + (FANBOYS) + Independent Clause

  • Although I was tired, I studied for the test, and I reviewed my notes.

These are powerful for weaving complex ideas and varying tone.

šŸ§  Visualization Metaphor:

Imagine sentence structures like architecture:

  • šŸ  Simple sentence = A one-room cottage

  • šŸ› Compound sentence = Two rooms, side by side

  • šŸ° Complex sentence = A room with a hidden corridor (dependent clause)

  • šŸ™ Compound-complex = A grand estate with multiple wings and secret passages

šŸ§  Why Sentence Variety Matters:

  • Keeps writing engaging and readable

  • Reflects tone and complexity of ideas

  • Emphasizes certain points while softening others

āœ Pro Tip for Writers:

Too many simple sentences? Your writing feels choppy.
Too many compound-complex? It feels dense or overloaded.
The key is to blend them like a composer mixing notes.