Questions & Answers about היא תמיד מתנהגת בנימוס, אפילו כשהיא לא מסכימה.
Because the subject is היא (she), and in Hebrew the present tense agrees with the subject’s gender and number.
- מתנהגת = feminine singular behaves / is behaving
- מסכימה = feminine singular agrees / is agreeing
Compare:
- הוא מתנהג... לא מסכים = he behaves... doesn’t agree
- היא מתנהגת... לא מסכימה = she behaves... doesn’t agree
So the -ת and the overall form tell you the subject is feminine singular.
The dictionary form is להתנהג, meaning to behave or to conduct oneself.
In this sentence:
- מתנהג = masculine singular present
- מתנהגת = feminine singular present
So היא מתנהגת means she behaves or she is behaving, depending on context.