__($key, $domain = ‘core’) – Translate strings
_e($key, $domain = ‘core’) – Translate strings (echo them)
_m($key) – Translate string (flash messages)
_n($single_key, $plural_key, $count, $domain = ‘core’) – Retrieve the singular or plural translation of the string.
_mn($single_key, $plural_key, $count) – Retrieve the singular or plural translation