Difference between Because and Because of
Because and because of are both used to introduce reasons. Because is a conjunction, and is followed by a subject and verb. Because of is a preposition, and is followed by a noun phrase or verb-ing
Because
because | subject | verb | |
because | he | felt | ill, he didn't go to the work |
Because of
because of | noun phrase or verb-ing | |
because of | his illness | he didn't go to the party |
because of | feeling ill |
And there is video from EngVid about it: