有關英文文法

has been + verb pp form = present perfect passive voice
has + verb pp form= present perfect active voice

就是主動與被動分別, 但是不是所有動詞也有passive voice, 而係transitive verb (物動詞), 字典會寫 vt , intransitive verb (vi) 係唔會有passive voice 被動式

"something" has been transferred = 被動 完成式
"somebody" has transferred "something" = 主動

has transferred -> 過去式
has been transferred -> 過去完成式

例句:
She has transferred to class B
She has been transferred to class B already

passive voice: has been transferred
active voice: has transferred