Sentences, Capital Letters & Full Stops
PrimaryA sentence is a complete thought wearing its uniform correctly: a capital letter at the start, and a full stop (or question mark, or exclamation mark) at the end. Get the uniform right and your writing instantly looks — and reads — like a real sentence.
What makes a sentence complete
A sentence needs two jobs filled: someone or something doing (the subject) and what they do (the verb). "The dog barked." has both — the dog is doing something, barked is what it did.
The three end marks
- Full stop (.) — for telling sentences: "The sun is hot."
- Question mark (?) — for asking sentences: "Is the sun hot?"
- Exclamation mark (!) — for excited or loud sentences: "The sun is so hot!"
Capital letters
Start every sentence with a capital letter, no matter which end mark it will get. Capitals also begin names (Chapter 3's proper nouns) and the word I always stands alone as a capital.
A capital letter is like a green traffic light telling the reader "a new sentence starts here — go!" An end mark is the red light telling them "stop, that thought is finished." Without these signals, sentences run into each other and the reader can't tell where one idea ends and the next begins.
"the cat sat on the mat it was fluffy" has no traffic lights at all — two thoughts are jammed together. Fixed: "The cat sat on the mat. It was fluffy." Now each idea gets its own green light and red light.
Activity: fix the broken sentences
my dog likes to run he chases the ball every day
After (fixed)My dog likes to run. He chases the ball every day.
What changed: a capital M starts the first sentence; a full stop closes it; a capital H starts the second sentence, which also ends with a full stop.
Now you try: fix "is it raining outside i forgot my umbrella" (Answer: "Is it raining outside? I forgot my umbrella.")
How do I know if a sentence is a question or a telling sentence?
ARead it out loud — questions usually make your voice go up at the end, and often start with a question word like who, what, where, when, why, or is/do/can. "Can you swim?" asks; "You can swim." tells. Same words, different order, different end mark.
Why is the word "I" always a capital letter, even in the middle of a sentence?
AIt's a special English rule going back hundreds of years — the single letter "i" looked too small and lonely on the page, so it was always written tall, as "I." Every other pronoun (he, she, they) only capitalises at the start of a sentence.
Can a sentence be very short, like just one word?
AYes, if it still gives a command with an understood "you": "Stop!" means "(You) stop!" — the doer is hidden but understood, so it still counts as a complete sentence.