Although or Allthough

Which spelling is correct, Although or Allthough, and how to use them properly.

INCORRECT
Allthough
This spelling is incorrect. "Allthough" is not a valid word in English.
CORRECT
Although
This is the correct spelling. "Although" is a conjunction meaning in spite of the fact that.
Definition
Although (conjunction): In spite of the fact that; even though.
Examples:
  • Although it was raining, we went for a walk.
  • Although he was tired, he continued working.
  • I enjoyed the movie, although it was quite long.
Synonyms
Words with similar meanings to "although":
Conjunctions:
  • Though
  • Even though
  • While
  • Whereas
  • Despite
Phrases:
  • In spite of
  • Regardless of
  • Notwithstanding
  • Even if
Note: "Although" is the correct spelling. "Allthough" is a common misspelling—remember, it only has one "l" at the start.
FAQ's
Is it allthough or although?
The correct word is "although." "Allthough" is a common misspelling.
How to pronounce although?
The correct pronunciation is /ɔːlˈðoʊ/ (awl-THOH).
What does although mean?
In spite of the fact that; even though.

Summary

Remember: Although is the correct spelling with single "l": al-though. It means despite the fact that or even though. The misspelling "allthough" is never correct. Always use "although" when introducing a contrast or concession.