名前だけでしか彼を知らない。

name; full name; given name; first name

only; just; merely; simply; no more than; nothing but; alone; as (e.g. as soon as, as much as); worth

be; is; indicates past or completed action; indicates light imperative

only; nothing but

he; him; his; boyfriend

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.

to be aware of; to know; to be conscious of; to cognize; to cognise; to notice; to feel; to understand; to comprehend; to grasp; to remember; to be acquainted with (a procedure); to experience; to go through; to learn; to be acquainted with (a person); to get to know; to concern