English proficient

← English fact (mention)

← Proto-Indo-European *pro- (root)

← Latin proficiens (mention)

← Latin proficere (mention)

← Latin pro (mention)

← Latin facere (mention)

→ English perfect (link)

→ English proficiently (suffix)

→ English nonproficient (prefix)

→ English profection (mention)

→ English unproficient (prefix)

→ English superproficient (prefix)

→ English haploproficient (prefix)

→ English proficientness (suffix)

→ English underproficient (prefix)

→ English overproficient (prefix)