Just some terminology before the actual question so you understand what "predicate nominative" really means.
Subject: Discussing the one who does something or is something in the sentence.
Predicate: Discussing the action which the subject does in the sentence.
In this sentence:
Subject: Chess
Predicate: has always been one of Henry's favorite board games.
Nominative: Describing the subject (words following <em>to be, to seem, </em>etc.)
Accusative: Taking a direct object (such as <em>to have, to see, to tell, </em>etc.)
Dative: Taking an indirect object (such as <em>to go <u>to</u>, </em><em>to look <u>at</u>, </em><em>to say <u>to</u>, </em>etc.)
Genitive: Possessing sth. (<em>Henry's, his, of the United States, </em>etc.)
<em>*note that nominative uses linking words and accusative/dative use action verbs.</em>
If you look in the sentence we have here, <em>been</em> is a paste tense of <em>to be</em>.
It is describing the subject as being one of Henry's favorite board games, and is thus using the nominative.
However, the term predicate nominative is a bit more specific than that, it's not referring to that entire phrase. It is just the object of that predicate, what the subject is being renamed to. Usually you can substitute <em /><em>equal</em><em>s</em> in the sentence and it should still work.
In this sentence, the predicate nominative is <u>games</u>. (Chess = game)
It’s the main idea of a piece of writing. It’s what an author is discussing and what the piece of work is focused on.
Mirikitani's "Attack the Water" relates to Rukeyser's "Poem" because they both focus on what civilians experience during wartime. "Attack the Water" describes the struggle of Vietnamese people living during (and after) the Vietnam War, and of Japanese-Americans in the era of Japanese Labor camps. "Poem" reflects on the struggle of people living during both of the World Wars, trying to get by and to get through such a tragic time. Both of these poems show that even when people are not involved directly in a war, war can still have an immense impact on their lives.