Can I borrow this?
A more literal and slightly more formal way to ask. It translates to 'Can I take this borrowed?'
Use this when the object you want to borrow is already clear from the context. 'Lo' means 'it'.
A very polite and slightly longer way to ask, meaning 'Can I ask you for this borrowed?'.
Excuse me, can I borrow your pencil? Mine has no point.
Can I borrow your charger? My phone is about to die.
What a nice jacket! For the party tomorrow, can I borrow it?
Sir, can I borrow this chair? We are missing one at our table.
The phrase '¿Me prestas...?' is universally understood and is the most common way to ask to borrow something across Latin America.
In Spain, it is much more common to use the verb 'dejar' (to leave/let). They would say '¿Me dejas esto?' instead of '¿Me prestas esto?'. Using 'prestar' is understood but less frequent in casual conversation.
While '¿Me prestas esto?' is used, it's very common to hear the 'vos' form: '¿Me prestás esto?'. Note the shift in stress and the accent on the 'a'.
'¿Me prestas esto?' is the standard and most natural-sounding phrase in both Mexico and Colombia for all levels of formality.
Saying '¿Puedo tomar esto?' — This translates to 'Can I take this?'. While it works for a free sample, for borrowing, it implies you are taking it permanently, not returning it. You must add 'prestado' at the end: '¿Puedo tomar esto prestado?'
Trying to find a direct verb for 'to borrow'. — Spanish expresses this idea from the lender's perspective. The verb is 'prestar' (to lend). So, instead of saying 'I borrow' (Yo presto), you say 'You lend me?' (¿Me prestas?). The concept is 'to ask for something on loan' (pedir prestado).
Using '¿Puedo prestar esto?' — This means 'Can I lend this?', which is the opposite of what you want to say. You are offering to lend something to someone else, not asking to borrow it.