Let's quickly review the main uses of
parentheses. And the singular of
parentheses is parenthesis. Now the main
use of parentheses is to add some extra
information in a sentence. And you can
see that here in our first example: our
extra information goes between brackets.
If you put the brackets right after the
subject of the sentence, so "The Human
Genome Project" is our subject, and then the
verb comes afterwards, "began." Do make sure
that you align your verb with the
subject before the brackets and ignore
the information that's inside the
parentheses.
So that's one thing to watch out for.
Another thing to observe is that this
information could also be put between
other punctuation marks at times. So in
this case we can use commas or dashes to
set off this information. And the effect
of using parentheses is that they draw
the least attention to this information;
it's almost like hiding it in a closet
or something like that by saying, you
know, "this doesn't really matter too much,
but if you did want to know this
information, well, here it is."
So parentheses really do not draw
much attention to that information. Often
you can use other punctuation marks but
not always. So in the next example here,
you can still use a comma or a dash
instead of parentheses. But in the last
example, if you were to use a comma here,
it just wouldn't work. And that's where
parentheses often allow you to break the
syntax of the rest of your sentence a
little bit, and you can then add
some extra information in a different
format. Do be careful though because it
is nice when if you were to take the
parentheses off, if the syntax keeps
going very nicely, it just blends a
little bit more smoothly. The second use
of parentheses is to add some citations
to show where you got your quotation or
where you got your information from.
And we've done that in both of these
examples. And as you look at this, do
notice that the period comes afterwards
in both cases, or other punctuation could
come there as well, if you have a
question mark or an exclamation mark.
And notice the space before our citation
just to make it look a little bit more
elegant. Our last major use of
parentheses is to organize lists. And you
can see how we've done that here with
numbers. You could use a different format
as well, so you could use letters if you
like. It's kind of up to you, but numbers
are often a good way to go. Let's finish
this explanation by just focusing
briefly on how parentheses interact with
other punctuation. So as you can see from
the first example, other punctuation
tends to go outside the parentheses, so a
period for instance. If you have a comma,
you should usually put it behind the
parentheses and not before.
If you have an entire sentence within
parentheses (not too common but it does
happen), you can put the period inside if
you like. If you are using punctuation
marks such as question marks or
exclamation marks, you have to kind of
decide where to put them.
So in the first example here, we've
decided that the whole thing is a
question. There's a question inside the
parentheses as well, of course, but all of
this is a question, and it's not really
necessary here to put an extra question mark inside
the parentheses as well. That would seem
kind of awkward, so we're just going to add
one question mark at the very end. In the next one
we've decided here that the thing that
really needs a little bit of emphasis is
what's inside the brackets, so we've
added an exlamation mark there, and then we've added a period
for the end of the sentence. In other
words, you have to kind of decide what
needs emphasis, where the question is,
where the punctuation needs to go. So be
aware of that and try to fit the
parentheses in as nicely as you can.