English UsageGrammar guide
Because vs. Because Of
Because introduces a clause that gives a reason, while because of is a two-word preposition followed by a noun phrase or equivalent nominal expression. They express similar cause relationships but take different grammatical complements.
Use because before a clause; use because of before a noun phrase or similar nominal expression.
Key details
Because Of Roletwo-word preposition meaning as a result of
Because Rolesubordinating conjunction introducing a reason clause
Complement Boundaryclause after because; noun phrase or nominal complement after because of
Further guidance
Clause Boundary
Because introduces a subordinate clause with its own subject and verb.
Preposition Boundary
Because of behaves as a preposition and takes a noun phrase or comparable complement.
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.
- Because, because of and cos, cos of — Cambridge Grammar (opens in a new tab)Cambridge Dictionary · Because before a reason clause and because of as a preposition before a noun phrase