Were or Was?

A company sergeant major asks:
I am responsible for checking all of my soldiers’ awards and report cards. The question came up about the use of “were” and “was”. Need some clarification:

His dedication to duty and determination was instrumental to the unit’s success.
His dedication to duty and determination were instrumental to the unit’s success.

Which is correct? Or are they both okay to use?

“Were” is correct, but I can see where the confusion arises. We might hastily read “dedication to” as applying to both “duty” and “determination,” which would make “dedication” the singular subject of the sentence...thereby requiring “was” as the verb.

But we are not “dedicated to determination.” This soldier has has two traits: dedication to duty is one, and determination is the other.

Turn the sentence around, and the verb is clearly “were”: His determination and dedication to duty were...

Comments

[Brett]

I would guess that the question is more about whether dedication was instrumental and determination was also instrumental, or whether it was the combination of the two that was instrumental. We often conceptualise thing as units and, where we do so, singular verb agreement is appropriate. In other words, both 'was' and 'were' are correct in the sentence in question, depending on what the intention was.

[Thandi McAllister]

My friends are arguing over which is correct:
I were a ballet dancer.
I was a ballet dancer.

Please clarify

[Crawford Kilian]

It should be "I was a ballet dancer."

However, when we use the subjunctive to describe a condition that isn't true, we can use "were" with a singular subject:

If I were a ballet dancer, I would be rich and famous. (But I'm not a ballet dancer!)

If I were you, I'd enter the contest. (But I'm not you!)

If he were as wise as he thinks he is, he'd keep quiet. (But he's not wise!)

[Joe]

Use was or were in this sentence:

"The contractor assume all spares that was purchased under the reference (a) contract are serviceable or in a serviceable condition".

[Crof]

Hi, Joe--

For grammar, the sentence should read: "The contractor assumes all spares that were purchased..."

For style, the sentence should read: "The contractor assumes that all spares purchased under the reference (a) contract are serviceable."

[Frank]

The inmates actions over the past two weeks was his worst.

The inmates actions over the past two weeks were his worst.

[Crof]

Hi, Frank--

The subject of the sentence is "actions," which is plural, so the verb should be "were."

[Benny]

Having set no boundaries for creativity, in-depth discussions concerning very specific parts of the BN were common.

or

Having set no boundaries for creativity, in-depth discussions concerning very specific parts of the BN was common.

? (and why?)

[Fusionzombie]

If only it was/were that simple?
any suggestions?