Question

Long ago,farmers milked cows by hand.

Is milked the action verb and by the linking verb also is use a linking verb

Answer 1

Yes, "milked" is the action verb.

This sentence does not have a linking verb.

Answer 2

"milked" is the action verb, yes -- and it's the only verb in that sentence.

"use" is an action verb, too

"by" is a preposition

Go here to learn about parts of speech:
http://www.chompchomp.com/terms.htm

http://www.ucalgary.ca/UofC/eduweb/grammar/index.htm

http://members.cox.net/lenco1/grammarpractice/