I have a question and thought that perhaps someone might help me.

I am assisting (or attempting to assist!) my son with his homework. Here are the directions he has been given:

"Change each underlined past-tense verb to its past form with a helping verb."

Example: We saw (underline) the performance of the best song.
Answer: We have seen the performance of the best song.

Below is the one that is stumping us:

The show was (underline) fun.

Your help would be most appreciated!
Robin & Justin
It'd be "The show has been fun".

Here, the Present Perfect is taught - so the simple past tense forms are changing to present perfect forms which consists of the helping verb "have /has" and the past participle, the 3rd form of the verb:
I have worked, you have gone, he has written, she has seen...

Hope I could help you.
Teachers: We supply a list of EFL job vacancies
Thank you very much.

I knew that when it was explained it would seem obvious!

Thank you again for helping me (us!)

Robin & Justin
No Problem, you're always welcome!
Hope to see you on here soon.