Singular - The Jones family has 10 people.
Plural - The Jones' have arrived.
This sentence needs more work as it really can't stand by itself. It just doesn't convey a complete idea. "The species" is the noun part; "at the bottom of the food chain" part is a defining clause modifying the noun which makes it a noun phrase. The sentence is not yet completed because it needs a predicate.
A predicate is the completer of a sentence. The subject names the "do-er" or "be-er" of the sentence; the predicate does the rest of the work. A simple predicate consists of only a verb, verb string, or compound verb:
The glacier melted.
The glacier has been melting.
The glacier melted, broke apart, and slipped into the sea.
A compound predicate consists of two (or more) such predicates connected:
The glacier began to slip down the mountainside and eventually crushed some of the village's outlying buildings.
A complete predicate consists of the verb and all accompanying modifiers and other words that receive the action of a transitive verb or complete its meaning. The following description of predicates comes from The Longman Handbook for Writers and Readers (examples our own):
With an intransitive verb, objects and complements are included in the predicate. (The glacier is melting.) With a transitive verb, objects and object complements are said to be part of the predicate. (The slow moving glacier wiped out an entire forest. It gave the villagers a lot of problems.) With a linking verb, the subject is connected to a subject complement. (The mayor doesn't feel good.)
A predicate adjective follows a linking verb and tells us something about the subject:
Ramonita is beautiful.
His behavior has been outrageous.
That garbage on the street smells bad.
A predicate nominative follows a linking verb and tells us what the subject is:
Dr. Couchworthy is acting president of the university.
She used to be the tallest girl on the team.
Go to the website I gave as a reference, it has color to help you follow what is meant.
