know

To know something is to understand it or have information about it. Or, “know” can be used when a thing or a person is familiar to you.  

know / knew / known / knowing

Use the word "know" for knowledge and skills:

  • Kathy knows algebra. 
  • She knows how to do algebra.  (know how + infinitive+ subject) 
  • Larry knows French. 
  • He knows how to speak and write in French. 
  • What are some things that you know how to do? 
  • Do you know how to sing? 
  • Do you know how to cook? 
  • Nowadays, most people know how to use a computer. 
  • It’s good to know how to do things for yourself. 

Use the word "know" for people:

  • Linda knows many people. 
  • She knows her neighbors. 
  • She knows the people with whom she works.
  • She knows a few people who can fix some things on her house. 
  • Bob knows his old friend Jerry very well. 
  • He knows what Jerry likes and doesn’t like. 
  • He knows Jerry’s family. 
  • Bob and Jerry have known each other for years. 

You can use "know" with most verb tenses, but it's not normally used with continuous tenses:

  • I know Jim. (Not, “I’m knowing Jim.”) 
  • Do you know what do do? (Not, “Are you knowing what to do?”) 
  • I have known Christine all of my life. (Not, “I have been knowing….” Do you get the idea?) 
  • Knowing how to swim is an important skill. (The word “knowing” is a gerund–not a verb–in this sentence.) 
  • It’s been nice knowing you. (This is an expression often used when saying goodbye to someone for the last time.) 

Here’s a video that I made for the verb “know” in 2015.