know and comprehend the nature or meaning of; "She did not understand her husband"; "I understand what she means"
perceive (an idea or situation) mentally; "Now I see!"; "I just can't see your point"; "Does she realize how important this decision is?"; "I don't understand the idea"
believe to be the case; "I understand you have no previous experience?"
make sense of a language; "She understands French"; "Can you read Greek?"