All Though vs. Although
“Although” is a single subordinating conjunction. Writing “all though” for that conjunction is a word-boundary error, although the separate words “all” and “though” can occasionally appear next to each other for unrelated grammatical reasons.
Use “although” as the conjunction meaning “despite the fact that.” “All though” is not an alternative spelling of that conjunction.
Key details
Further guidance
Core difference
Use the single word “although” when you mean “despite the fact that” or introduce a concessive subordinate clause.
Fast Test
If the phrase can be replaced by “even though” at the start of a concessive clause, write “although” as one word.
Usage Boundary
Do not automatically join every adjacent “all” and “though”: they can occur as separate words when each has its own grammatical job, but that is not a variant spelling of “although.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- ALTHOUGH — Cambridge Dictionary (opens in a new tab)Cambridge University Press & Assessment · Direct dictionary and grammar evidence for although as a single subordinating conjunction.
- THOUGH — Cambridge Dictionary (opens in a new tab)Cambridge University Press & Assessment · Direct dictionary and grammar evidence for though as a conjunction/adverb, supporting the boundary between although and separate all + though sequences.