because vs if only

because

conj
  • As is known, inferred, or determined from the fact that. 

  • By or for the cause that; on this account that; for the reason that. 

adv
  • On account (of), for sake (of). 

  • Used alone to refuse to provide a full answer a question begun with "why", usually taken as an anapodoton of the elided full phrase "Because I said so". 

prep
  • On account of, because of. 

if only

conj
  • Used other than figuratively or idiomatically: see if, only. 

  • I wish that; signifies a wish or desire for the present or the future. 

  • I wish that; signifies a regret about an action in the past. 

  • Even if for no other reason than; only just. 

How often have the words because and if only occurred in a corpus of books? (source: Google Ngram Viewer )