English Idioms and Expressions 

Idioms: Intelligence, Smartness and Comprehension-2
from:  'common knowledge'  to: 'hammer home'

• common knowledge
  • When information is well-known to everyone (particularly in a community or group), it is called common knowledge.
    "You didn't know the intern was Jack's son? It thought it was common knowledge."
    
    
• credibility gap
  • The extent of disbelief, of the difference between what you are asked to believe and what you are able to believe, is call a credibility gap.
    "The growing credibility gap may lead to a serious loss of votes in the next elections."
    
    
• at cross purposes
  • If two people areat cross purposes, there is a misunderstanding as to what each one is talking about.
    "Look, we seem to be at cross purposes. You're talking about 'sailing' boats, but I'm talking about 'selling' boats."
    
    
• crystal clear
  • A statement or expression that is easy to understand or has an obvious meaning is crystal clear
    "There's no need to repeat the instructions. They were crystal clear."
    
    
• dumbing down
  • If something, such as a television programme or a film production, is dumbed down, it is deliberately made less intelligent or less demanding in order to attract a larger audience.
    "Some TV channels are dumbing down their programmes in an attempt to increase their audience ratings."
    
    
• enough said
  • This expression is used to indicate that you completely understand the situation and you do not need any further details.
    "Your mother-in-law arrived unexpectedly last night? Enough said!"
    
    
• eyes (wide) open
  • If you do somethingwith your eyes open, you are fully aware of what you are doing.
    "I took on the job with my eyes wide open so I'm not complaining"
    
    
• facts speak for themselves
  • When the facts of a situation are so clear that no further explanation or extra details are necessary, the facts speak for themselves.
    "No need to tell you that the situation is disastrous. The facts speak for themselves."
    
    
• get someone's drift
  • If you get someone's drift, you understand in a general way what they are trying to say.
    "I didn't understand every word but I got the drift."
    
    
• get the message
  • If you get the message, you understand what someone is trying to tell you, even if it is expressed in actions or gestures rather than words.
    "When Tony pointed to his watch, I got the message - it was time to leave for the airport."
    
    
• get the picture
  • A person who gets the picture understands what is being explained or described.
    "The alarm went off and people started running everywhere - you get the picture I'm sure!"
    
    
• (it's all) greek to me!
  • This expression means that you do not understand what is being said or written or that you find it incomprehensible.
    "He showed us a complex diagram to illustrate his idea but it was all greek to me!"
    
    
• get wise to something
  • If you get wise to something, you learn something that you were not aware of before.
    "The old man finally got wise to the fact that children were stealing apples from his garden."
    
    
• go over your head
  • If something said or written goes over your head, you find it too difficult to understand or follow.
    “I always found mathematics difficult at school. The teacher’s explanations just went over my head!”
    
    
• grey matter
  • Grey matter refers to the brain, or the grey colour of brain tissue. The term is used to refer to comprehension.
    "Try using your grey matter and you might find the answer." said the teacher.
    
    
• hammer something home
  • If you hammer home a point or an argument, you repeat it often to make sure that it is fully understood.
    "The police hammered home the dangers of drinking and driving."