I locked myself out
Use this to explain the reason you are locked out. It means 'I left the keys inside.'
A very simple and direct way to state the problem. It means 'I can't get in.'
This translates to 'The door closed on me.' It's a common way to remove blame, implying it was an accident.
Help, please! I locked myself out of my apartment.
I think I left the keys inside the car. What do I do now?
Excuse me, can you help me? The door closed on me and my cell phone is inside.
I called my friend to bring me his copy of the key because I can't get in.
The phrase 'Me quedé afuera' is universally understood. Explaining 'Dejé las llaves adentro' is also common everywhere.
In Spain, it's much more common to use the present perfect tense for recent events: 'Me he quedado fuera'. They also use 'coche' for car and 'móvil' for cell phone.
'Me quedé afuera' is standard. You will also frequently hear 'Se me cerró la puerta', using a special grammatical structure (the 'accidental se') to imply the event was an accident and not your fault.
'Me quedé afuera' is the most common phrase. People might also specify 'Dejé las llaves por dentro' to mean 'I left the keys inside.'
The standard phrase 'Me quedé afuera' is used. There are no significant variations for this particular expression.
Saying 'Yo me cerré afuera'. — This is a direct translation of 'I closed myself outside' and sounds unnatural. Spanish focuses on the resulting state ('I stayed outside' - 'Me quedé afuera') rather than the action of locking.
Using 'bloquear' like 'Me bloqueé afuera'. — 'Bloquear' means 'to block' (like a road or a phone number). It is not used for locking doors. Stick to 'quedarse afuera' or explain that you left the keys inside.
Forgetting the reflexive pronoun 'me'. — Saying 'Quedé afuera' instead of 'Me quedé afuera' is grammatically incorrect in this context. The 'me' is essential to show that this is something that happened *to you*.