Questions & Answers about Þær talast ekki við en þær eru kurteisar.
How does talast við mean "speak to each other"?
The regular verb phrase is tala við (to speak to/with). By adding the -st ending to make it middle voice, the action becomes reciprocal. Instead of one person speaking to another, the -st ending shows they are doing it to each other.
Why is ekki placed between talast and við?
Við is a preposition working closely with the verb here. In Icelandic, adverbs like ekki (not) normally come right after the conjugated verb, but before any prepositions or particles attached to it. That's why it interrupts the phrase, giving us talast ekki við.
Why are we using Þær for "they", and why does the adjective have an -ar ending?
How would this sentence change if "they" referred to a mixed group of men and women?