Koni and Scii.
237 (c). Koni and scii are used in the same sense as the French verbs connaître and savoir.
Koni means to know, to be acquainted with, to know a person, or, thing.
Examples.—Mi konas vian fraton = I know your brother. Li konas la hundon, sed li ne konas ĝian posedanton = He knows the dog, but he does not know its owner.
N.B.—It is never followed by the conjunction KE; Mi konas, ke, is wrong. Mi scias, ke vi ... = I know that you ...
Scii means to know, to be aware of, to know something is or was happening, etc.
N.B.—It is never used of persons.
Examples.—Mi scias, ke li estas prava = I know that he is right. Mi sciis, ke li estis tie hieraŭ = I knew he was there yesterday. Mi ne sciis, ke vi konas lin = I did not know that you knew him. Mi konas la francan lingvon, sed mi ne scias ĝin = I know (recognize) the French language (when I see it), but I do not know it.
Lasi.
237 (d). Lasi, like the English verb "to leave," has various meanings.