Mal-, -in-.
In Esperanto certain syllables which have a definite meaning are placed
at the beginning (prefixes) or end (suffixes) of words to alter in some
way the meaning of those words.
The prefix "mal-" gives an exactly opposite meaning to the word to which
it is prefixed, as "dekstra", right (hand); "maldekstra", left (hand);
"nova", new; "malnova", old; "helpi", to help, "malhelpi", to hinder;
"fermi", to shut, "malfermi", to open.
The suffix "-in-" denotes the female sex. From "viro", [Footnote: The
word "homo" previously given (Lesson 2) signifies a human being, a
person, without reference to sex; "viro" means a man as distinguished
from a woman.] a man, we get "virino", a woman; "filo", son, "filino",
daughter; "cxevalo", a horse, "cxevalino", a mare; "koko", a cock,
"kokino", a hen.