'is'.
It's from the verb 'ser' = 'to be' and is used for more-permanent 'being'. The verb 'estar' (also 'to be') relates to temporary states, e.g. location.
For example:
Es inteligente = He is intelligent
Esta muy contento = He is very content
"Es" and "son" mean "is" and "are" in Spanish.
"Es lunes" is Spanish for "It's Monday".
no = no and es means is
"es' is not a prefix in Spanish.
"Si es, es" is Spanish for "If it is, it is". If you just mean "si es", that means "if it is". If you mean "Sí es" (with an accent on "Sí"), it means "Yes, it is".
it is a...
Where is it or where.
is the
"Es nuevo" means "it is new" in Spanish.
"Asi es amiga" in Spanish translates to "That's how it is, friend" in English.
what is this
It means: What is...