Let someone know (about something)
To tell someone something; to inform someone of something.
Example : Please let me know about it soon. Will you be coming to the picnic? Please let me know.
Used to introduce a suggestion or possible example of something.
Example :Try and finish the work by, let’s say, Friday.
Let’s see (spoken)
It means you are thinking about it, you want to discover more of it.
Example : “Do you have any idea how many people will be there?” “Well, let’s see – I don’t think I could put a number on it.”
Let me see (or think)
Used when one is trying to remember something or considering one’s next words.
Example : “Now let me see, where did I put it?”
Let’s call it a day.
Let us end what we are doing for the day.
Example : Mary: Well, that’s the end of the reports. Nothing else to do.
Sue: Let’s call it a day.
Bob: Let’s call it a day. I’m tired.
Tom: Me too. Let’s get out of here.
Let’s shake on it.
To agree on something by shaking hands on it.
Example : Bob: Do you agree?
Mary: I agree. Let’s shake on it.
Bill: Good idea. Sounds fine.
Bob (extending his hand): Okay, let’s shake on it.
Bill (shaking hands with Bob): Great!
Let it (things) slide
To allow a situation to become slowly worse.
Example : We’ve really let things slide over the past few months. The accounts are in a terrible state.
Let someone in on (something)
To allow to know about something, allow to share something.
Example : I’m going to let you in on a little secret.
To allow someone or something to escape or go free.
Example : The kidnappers they let the hostages go.
Let your guard down
To stop guarding oneself against trouble.
Example : He never lets his guard down because he trusts no one.