Extraño vs. raro
The Spanish words 'extraño' and 'raro' both translate to 'strange' or 'odd' in English, but they have subtle distinctions in usage and connotation.
Extraño
'Extraño' often refers to something that is foreign, unfamiliar, or not common. It can denote a sense of unfamiliarity or something that is out of the norm.
Este lugar me resulta extraño.
(This place feels strange to me.)
Es extraño que no haya llegado todavía.
(It's strange that he hasn't arrived yet.)
Vino acompañado de un hombre extraño.
(He came accompanied by a strange man.)
Raro
'Raro' often implies something unusual, uncommon, or odd in a way that may be peculiar or even suspicious. It generally carries a stronger connotation of weirdness than 'extraño'.
Es raro encontrar flores en el desierto.
(It's rare to find flowers in the desert.)
Su comportamiento ha sido muy raro últimamente.
(His behavior has been very odd lately.)
Hay un olor raro en esta habitación.
(There is a weird smell in this room.)
Summary
In summary, while both 'extraño' and 'raro' can mean strange or odd, 'extraño' often highlights unfamiliarity or foreignness, and 'raro' tends to emphasize unusualness, peculiarity, or weirdness.