Conjugation is a very long word, isn't it? In grammar, when you conjugate a verb, it just means that you change the verb in order for a sentence to make sense. Correctly conjugated verbs ...
Normally in the past tense, you do not need to worry about subject-verb agreement because you can conjugate most regular past tense verbs to the singular or plural by adding an -ed to the end of the ...
Instead of opting for bland, unspecific expressions ("says," "writes about," "believes," "states") consider using more vivid or nuanced verbs such as "argues," "insists," "explains," "emphasizes," ...