Proper use of the prepositions por and para can be difficult for non-native Spanish speakers because of their variety of meanings. Both of them usually mean "for". Let's focus on their uses.

para:

• "purpose" (in order to) or "use"
• to indicate "destination" (location or recipient)
• convey the time limit of a particular action
• considering (that)
• express suitability
• "in my opinion"

por:

• express the reason or motive for an action
• indicate a place where movement is occurring
• periods of time: parts of the day
• por = per
• express price or an exchange
• por + manner or means of transportation
• agent of passive voice (por = by)
• the object of an errand with verbs like: ir, enviar, mandar, venir, etc.
• with estar to express "to be about to"

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