The verb substitute has very different understandings depending on the prepositional company it keeps. For example, ask a barista, Can I substitute regular milk for lactose-free milk? and you’re usually asking for regular milk, not lactose-free...
In the U.S. the verb mooch means “to get something without paying for it.” In the UK, mooch means “window shopping.” Linguist Lynne Murphy writes about this and other differences in her helpful blog, Separated by a Common...