iksā is for a single person, whereas iksāt is plural. Riñi is plural, so iksāt is used.
- Riña iksā. You are a girl.
- Riñi iksāt. You are girls.
Present indicative of the verb: sagon to be
- iksan I am
- iksā you are (singular)
- issa he/she/it is
- iksi we are
- iksāt you are (plural)
- issi they are