An exclamation is a “sharp or sudden utterance.” It stands alone and is punctuated by an exclamation point. 

Whee! Whoa! Ugh!

A sentence that follows an exclamation is not part of the exclamation. If the sentence requires an exclamation point, an exclamation point is used. If the sentence expresses bleak and pessimistic sentiment, it is punctuated by a period. 

Darn these new meds! I’ll have to accept that my libido is gone forever. 

Use an exclamation point when warning of imminent danger or suspiciously timed accidents. 

Look out for that bus!

Use a period when confusing danger with paranoia.

Everyone wants to hurt me.

Aggressive, repetitive use of exclamation points cannot make a statement true. Denial is best punctuated with a period.

Absinthe is an FDA-approved medication for bi-polar disorder.

An exclamation point is often required after excessive self-medicating.

Get out of my way! I’m going to be sick!

Use a period when expressing remorse or shame after meaningless sex with a stranger.

I feel dirty.

Use an exclamation point if the meaningless sex was unprotected and unsatisfying.

Holy hell! That was a stupid and desperate stab at intimacy.

When pairing a self-denigrating exclamation with a question, put the exclamation point before the question mark. 

When will I ever learn!?

Or after.

You idiot! Why didn’t you get her number?!

False justification for a loss of interest in activities you once found pleasurable, such as masturbation, eating and breathing, rarely requires an exclamation point.

In Boy Scouts they told us self-gratification is unhealthy and ungodly.

Use a period when lacking the energy or motivation to get out of bed for week-long stretches of time.

I really should empty this bedpan.

Use a period when politely dismissing a friend’s or relative’s concern for your reclusive habits and poor hygiene.

Let me be, please. I like the way I smell.

An exclamation point may be used when, in a rare display of assertiveness, you repudiate a friend or relative who repeatedly insists you smell bad and you look pallid and sickly.

 Go to hell!

Multiple exclamation points may be used if said friend or relative also uses words or phrases like “increased dosage” and “electroconvulsive.”

You’re not my shrink!!!

Use an exclamation point when the voices in your head are yelling.

You’re no good! You’ll never amount to anything no matter how much rebirthing therapy             you get!

Use a period when the voices mumble fatalistic negative self-talk.

 My life is a steaming pile of turds and it will never get better—ever.

Use a question mark when the negative self-talk is rhetorical.

Would anyone really care if I drank this entire 32-ounce bottle of Liquid Plumber?