Learning is difficult.
Math class is very difficult.
"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".
"Es" and "son" mean "is" and "are" in Spanish.
El maestro de español es la persona encargada de enseñar la lengua española a los estudiantes. Su función principal es impartir lecciones, corregir trabajos escritos y fomentar el aprendizaje del idioma en el aula.
Es - Is
sistemas de aprendizaje
quis es means "who are you?"
"Qué es" means "what is". "Quién es" means "who is."
Mañana es. = Tomorrow it is.
Es means "it" in English.
no = no and es means is
"es' is not a prefix in Spanish.