Put on a mask
The Spanish phrase 'ponerse una mascarilla' translates to 'put on a mask' in English. It may be used in various contexts, such as a reminder for personal safety measures during health crises or indicating the act of applying a facial beauty mask. 'Ponerse' is the reflexive form of the verb 'poner', which means 'to put'. 'Una' is an indefinite article equating to 'a', and 'mascarrila' specifically means 'mask'.
I would recommend that you put on a mask before using public transportation.
In this sentence, the recommendation of wearing a mask is given to the listener before they consider using public transportation.
Before entering the hospital, it is necessary to put on a mask.
In this sentence, the action of putting on a mask is presented as a requirement or necessity before entering a hospital to prevent the spread of diseases.
If you want to avoid contagion, you should put on a mask when you are in public places.
In this sentence, wearing a mask is advised as a preventive measure against contagion when someone is in public places.