Give, please, a detailed explanation between the next phrasal verbs:

  1. to lock out
  2. to lock in
  3. to lock down

I am especially confused between the meanings of "lock out" and "lock in", they are similar by meaning but have different prepositions, "get in and get out" - it's ok they differ by opposite actions...

  • 2
    A door has two sides. One side is "in", the other, "out". And there are doors of different kinds: prison cell doors, house doors, warehouse doors, etc. I would think that only the preposition down might give you some trouble.
    – TimR
    Commented May 30, 2018 at 19:50

3 Answers 3


to lock out - Something is locked and you cannot get into it, so it is locked and you are out (outside). You lost your key at the pub and the door to your house is locked, you are locked out (outside). You could also lock your spouse out of the house if you are angry.

This is also commonly used for smartphones and computers in the same way. You may be locked out (cannot use the phone/get into the phone) until you enter a code or password or you are locked out for a time because you failed multiple times.

to lock in - Something is locked and you cannot get out of it, so it is locked and you are in (inside). You got into a fight at the pub, the police arrest you and you are locked in (inside) a jail cell. You could also lock yourself in the bathroom if you are angry at your spouse.

This may also mean something of a contract or guarantee. Something that can be "fixed" or restricted from change. If you sign the loan contract today then your interest rate is locked in at 4% and cannot change.

to lock down - One meaning is a combination of lock in and lock out. If there is a security crisis at a building, campus, prison etc. it may be locked down, or in lock down. No one comes in or out and movement of people inside may be restricted.

Also used in reference to computers or information systems to represent that security controls have been tightened to only allow certain authorized access and functions.


The word lock (used as a verb) can be followed by several prepositions.

to lock out

means to prevent a person/people getting into a room/building/institution

to lock in

means to prevent a person/people getting out of a room/building/institution

to lock down

is a phrase used to describe the action by security forces when they surround a building and prevent anyone from entering or leaving, typically in a situation involving terrorists or individuals posing a threat.

to lock up

means to detain or to imprison when it's used of people,

and to keep under lock and key when it's used of objects.

People can also lock themselves into or out of vehicles and buildings accidentally and often do.


"To lock out" and "to lock in" differ in a very similar way to "get in" and "get out", actually. If I lock someone out, I have locked something such that they cannot get in (i.e., they are trapped outside the thing I locked). If I lock someone in, I have locked something such that they cannot get out (i.e., they are trapped inside the thing I locked).

This is reflected by the definition in Cambridge Learner's Dictionary:

lock sb in/out
to prevent someone from entering/leaving a room or building by locking the door

but the order they use is confusing -- "lock in" is to prevent from leaving, "lock out" is to prevent from entering.

You ask for "lock down", but I'm also going to include "lock up", since it's another lock + preposition phrasal verb that can be confusing. Unlike "lock in" and "lock out", "lock up" can take either a person or a thing as its object. When you lock something up, you're locking all the doors/windows/etc. of something, usually as you leave or go to sleep or something. When you lock someone up, you're locking them in somewhere -- usually a prison or something similar from which they cannot escape

"To lock down" typically takes a prison, school, or other important institution (like a governmental facility) as an object, and it describes elevated security measures in which you make the people involved (prisoners, students, etc.) stay locked inside their cells/rooms/etc. during an emergency for safety/security purposes. Police will "lock down" an area after a crime, for instance. It's also often described as "going on lockdown", particularly when it's a school involved, and many schools (at least in the US) have what are called "lockdown drills" where they practice locking down the school in case there's a school shooter or bomb threat.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .