Answer:
The incorrect verb is "make" and will be replaced by "makes".
So, the final corrected sentence will be - Either baby kale or spinach makes a nice addition to Tuscan white bean soup.
Explanation:
Subject-verb agreement refers to the use of the correct form of verb for the subject in the sentence. This means that the verb depends on the subject/ subjects and should be used accordingly.
In the given case, the use of "either/or" is one case where the verb will be according to the subject nearest to it. So, in the given sentence, the subject nearest to the verb "make" is spinach which is single. Either way, the subjects in the sentence are both singular, which makes the verb to be in the singular form.
Therefore, the incorrect verb form is "make" which will rather be "makes".
Thus, the final corrected sentence will be-
<em><u>Either baby kale or spinach makes a nice addition to Tuscan white bean soup.</u></em>
