上着を今着ているところだ。

coat; tunic; jacket; outer garment

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.

now; the present time; just now; soon; immediately; (one) more

to wear (in modern Japanese, from the shoulders down); to put on; to bear (guilt, etc.)

place; spot; scene; site; address; district; area; locality; one's house; point; part; space; room; whereupon; as a result; about to; on the verge of; was just doing; was in the process of doing; have just done; just finished doing

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