Present Indicative

We've learnt that in Greek we don't use pronouns (I, you, we....) much, because the ending of the verb always tells us WHO does it.
We know  -ω and -ῶ endings for: I (personally) do it.
We've also seen  -εις and -εῖς endings for: you (whom I'm addressing) do it.
And we've known for ages that -ει and -εῖ endings mean: he, she or it does it.
 
Now the verb TO BE is a totally different proposition altogether, just like in English. And in most other languages. A law onto itself!
 
Singular Forms of TO BE:
 1st person singular:   I  am   εἰμί
 2nd person singular:   you  are   εἶ  
 3rd person singular:   he, she, it  is     ἐστί(ν)