'Through' means "from one side to the other"; 'though' means "although". They look similar but have nothing in common.
"Through" is a preposition indicating movement from one side of something to another, or the passage of time/process: "walk through the door", "through the year".
We drove through the tunnel and came out on the other side.
She's been through a lot this year, but she's still smiling.
Just push the door and walk through, it's not locked.
"Though" is a conjunction meaning "although", used to contrast two ideas. It's also used informally at the end of a sentence, similar to "however".
It's expensive, though I think it's worth it.
He said he'd come. He didn't show up, though.
Though she was tired, she finished the report before midnight.
Common mistake
The spellings are easy to mix up because both start with "th" and share similar letters. To remember: "through" has an "r" right after "th" (th-R-ough), while "though" doesn't.
Trick to remember it
"Through" has an extra "R" (T-H-R-ough), think "R for route": you travel a route from one side to the other. "Though" has no "R", and means the same as "although".
Quick rule
Is it "from one side to the other" of a place or process? "Through". Is it "although", contrasting two ideas? "Though".
Did you know?
"Through" and "though" belong to a notorious group of English words ending in "-ough" that are pronounced in completely different ways: "though" rhymes with "go", "through" rhymes with "blue", "rough" rhymes with "stuff", and "cough" rhymes with "off". This chaos exists because English kept the medieval spelling while pronunciation kept changing over time (the "gh" originally sounded like a guttural "j", as in German "Nacht"), leaving the spelling "frozen" in the past.
Exercise 1 · Pick the right one
The train goes _____ three tunnels before reaching the station.
Exercise 2 · Pick the right one
I don't really like the color, _____ I have to admit it looks great on you.
Exercise 3 · Form the word
'Though' means "although"; 'thorough' means "careful and complete". They share almost every letter but nothing else.
One means to receive or agree to something, the other means to exclude or not include.
'Advice' is the guidance you receive (noun); 'advise' is the act of giving that guidance (verb).
'Affect' is the verb meaning to influence something; 'effect' is the noun meaning result or consequence.
Bryan López
Founder of SpeakUP Academy