We were supposed to label every word in these sentences, but some of them were kind of confusing:

The process is a method using heat and cold.

I know that "the" is article adj., "process" is subject, a article adj, "and" is a conjunction , but what is the rest.

He showed scientists the potentiallty of controlling bacteria or germs.

would "of controlling bacteria or germs" be all one prepositional phrase if not what would it be?

I'll get you started.

He = pronoun, subject
showed = verb, past tense main verb
scientists =
the =
potential (no such word as potentiality) =
of = preposition
controlling = gerund
bacteria =
or =
germs =

This website should help:
http://grammar.ccc.commnet.edu/grammar/
Use the menu in Word & Sentence Level to find functions of words.

Let me know what you come up with and I'll give you feedback.

=)

what is gerund. and I didn't say it was potentiality, I said potentiallty.
The end of the word spelled with a l...l...t...y

The word should be "potential" -- no "allty" on it; no such word as "potentiallty"!!

Gerunds:
http://owl.english.purdue.edu/handouts/grammar/g_verbals.html

http://grammar.ccc.commnet.edu/grammar/verbs.htm#gerunds

=)

A gerund is a verb that functions as a noun in a sentence. It is formed by adding -ing to the base form of a verb. In the sentence you provided, "controlling" is a gerund because it is a verb (control) that is being used as a noun.

As for the rest of the sentence:

scientists = noun, object of the verb "showed"
the = article adjective
potential = noun
of = preposition
controlling = gerund
bacteria = noun
or = conjunction
germs = noun

Sorry for the confusion about the word "potentiality," it was a misunderstanding on my part. It should be "potential" without the "allty" at the end. Thank you for pointing that out.

You can find more information about gerunds and other grammar topics on the websites I provided earlier. They should help you understand the functions of words in a sentence. Let me know if you have any more questions!