If you don't define a tag file but you do use BNC data, you will get concordance results looking somewhat like this:
XML edition
Here just before the search-word, Concord has shown you the <w c5="AJ0" hw="terrible" pos="ADJ"> tags which show that terrible is an ordinary adjective (not comparative or superlative) belonging to the head word "terrible" and that it is an adjective.
Earlier editions
Here just before the search-word, Concord has shown you the <w AJ0> tags which show that terrible is an ordinary adjective.
You can see or hide these tags as you prefer.
If you hide them you will see something like this: