SEE,SEEN

If I could rid the speaking public of the verb construction I SEEN, I would . . . quickly and severely.

Verb Tenses: PRESENT:  I see the aardvark. PAST: I saw the aardvark. Past Perfect: I had seen the aardvark.
Such a simple rule! Seen must have a helping verb.
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I scream and gnash my teeth when I hear news commentators say, "I feel badly."

 Bad is an adjective. Badly is an adverb [words ending in ly  with/ a few exceptions].

• I is the subject of the sentence.
• Feel is a linking verb. [Remember the linking verbs:is, am, are, was, were, be, being, been, seem,appear, feel, grow?]
• Adjectives follow linking verbs, Feel is a linking verb. Bad is an adjective. xxxxxxxxxxxxxxxxxBadly is an adverb.
• Therefore, the correct construction is "I feel bad."