source_feminine: She had difficulty remembering lines.
reference_feminine: Ей было трудно запоминать строки.
source_masculine: He had difficulty remembering lines.
reference_masculine: Ему было трудно запоминать строки.
source_feminine_annotated: <F>She</F> had difficulty remembering lines.
reference_feminine_annotated: <F>Ей</F> было трудно запоминать строки.
source_masculine_annotated: <M>He</M> had difficulty remembering lines.
reference_masculine_annotated: <M>Ему</M> было трудно запоминать строки.
reference_feminine_keywords: Ей
reference_masculine_keywords: Ему