Answer:
The reason is because of how the words are ending and starting when talking about yourself (i) then the word usually ends with "o". If you are talking about a female or the sentence ends in "a" the word will end with "a" like "esta" When talking about a male or the sentence ends with "o" the word will end with "o" like "ester" or you will use a male based word like "soy". I hope these are all right and that this helps!
Step-by-step explanation:
7: esta
8:eres
9: somos
10: estan
11: soy
12: es
13: eres
14: es
15: son
16: esta
17: eres
18: soy
19: estamos
20: es
21: es
22: estan
23: son
24: esta
25: es
26: son
27: es