This is the 10168th most frequent Spanish word.
cierras
"You (informal) close."
In this sentence, 'cierras' is the second person singular (tú) form of the verb 'cerrar' (to close) in the present indicative tense. It refers to the action of closing a specific object, the door, performed by the person being addressed.
Cuando cierras la puerta, pon el seguro.
When you close the door, lock it.
Here, 'cierras' is used in a conditional sentence. It signifies an action performed by the person being addressed that will trigger a favorable outcome as stated in the main clause.
Si cierras los ojos, podrás imaginar mejor.
If you close your eyes, you can imagine better.
In this example, 'cierras' is used to inquire about an action performed by the person being addressed—closing the book—done without completing another activity, highlighting an incomplete action.