彼はあなたをとても愛しています。

he; him; his; boyfriend

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

you (referring to someone of equal or lower status); dear (what a wife calls a husband)

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

very; awfully; exceedingly; (not) at all; by no means; simply (cannot)

to love