Mendigo vs. pordiosero

The Spanish language is rich with synonyms and possesses a number of words with similar meanings. In this case, 'mendigo' and 'pordiosero' both translate to 'beggar' in English. However, they do carry subtle differences in their connotations and usage.

Mendigo

A mendigo is generally used to refer to any person who begs or asks for alms. The term doesn't carry a specific cultural or regional connotation, making it a more universally understood term across the Spanish-speaking world.
El mendigo se sentó en la esquina de la calle pidiendo limosna.
(The beggar sat on the corner of the street asking for alms.)
No todos los mendigos están sin hogar; algunos tienen un lugar para vivir pero no tienen empleo.
(Not all beggars are homeless; some have a place to live, but they don't have jobs.)

Pordiosero

A pordiosero also refers to a person who begs, but this term often implies a deeper level of desperation - literally translating as 'for God's sake'. This word is less commonly used in general Spanish speaking world today, and typically conveys a slightly more negative or pitiful connotation than 'mendigo'.
El pordiosero estaba desesperado por comida y abrigo en el duro invierno.
(The beggar was desperate for food and shelter in the harsh winter.)
La mujer era una pordiosera que pedía en las calles para alimentar a sus hijos.
(The woman was a beggar who begged on the streets to feed her children.)

Summary

While both 'mendigo' and 'pordiosero' refer to individuals who beg or ask for help, 'mendigo' is more universally used across Spanish-speaking regions without any particular connotation. On the other hand, 'pordiosero' bears a tone of deeper desperation and negativity - often perceived as slightly more pitiful or desperate than a 'mendigo'. Nonetheless, context would be key when using these terms as meanings could shift depending on use case scenarios.