Language changes all the time. Grammar, prunounciation, and most importantly, words. Some people think that the change of meanings of words is a bad thing. 

The English language is full of words of which the meaning has changed over time. Awful used to mean awe inspiring, for example. Other things can change too. 

Certain words are used in different dialects. To lend and to borrow are two words that are slightly different, but in a lot of dialects they are used interchangeably. 

Some things can be more complicated because words can have multiple meanings, but with a little bit of extra context, this is easily resolved like with "I mean funny ha-ha, not funny particular.