hey!! i have always struggled with helping + linking verbs so if someone could help me out here that would be great :)

which sentence(s) contain a helping verb?

"She refuses to take sides."
"He wields a sword in battle."
"She was struggling against the army."
"She is a genius."

//

which sentence(s) contain a linking verb?

"He is powerful."
"Dr. Strange is an Avenger."
"She was stuck in a web."
"He was chasing them down a dark alleyway."
"He is a liar."

thank you all so much <3