Breakdown of Esas chicas se odian y no se soportan.
y
and
la chica
the girl
no
no / not
se
himself / herself / themselves (reflexive)
Questions & Answers about Esas chicas se odian y no se soportan.
How do we know se means "each other" here and not "themselves"?
In this context, se odian translates best to "they hate each other" because it is a mutual action between the girls. While it could grammatically mean "they hate themselves" (a reflexive action), common sense usually makes it clear when an action is reciprocal. If you ever need to be completely clear that it is reciprocal, you can add la una a la otra at the end.
Why is the negative word no placed before se soportan instead of after?
In Spanish, the negative word no always goes immediately before the object pronoun attached to the conjugated verb. So it must be no se soportan, never se no soportan.
Does soportar mean "to support" in English?
No, soportar is a false friend. It actually means "to stand," "to bear," or "to tolerate." So no se soportan means "they cannot stand each other." If you want to say "to support" emotionally or financially, you would use the verb apoyar.
Could we use nos or os instead of se in this sentence?
Not for esas chicas, because that refers to "they" (third person plural), which requires se. If the sentence were about "we" (we hate each other), you would use nos odiamos, and for the informal plural "you all" in Spain (you all hate each other), you would use os odiáis.