Humanity is on the verge of extrasolar colonization when an alien race reveals to us that we are carriers of an incurable virus that could wipe out life in the universe if it ever spread beyond our stellar system.
Technically, friends, only the system centered around Sol is a solar system; the correct generic term is stellar system.
Speaking of generic terms, alien is a generic adjective, not one derived from a proper noun, so don’t capitalize it.
(And speaking of alien, I always hated how the people on the Babylon 5 space station were described as “humans and aliens” rather than just as people.)
Mercenary Proofreader is not impressed by the bio-science ignorance of these aliens. Obviously humans aren’t dying of the virus, so there must be something about humans that makes ’em resistant, immune, whatever. Couldn’t someone, y’know, study the disease-resistant species and figure out why they’re not dying, and then apply that knowledge to giving immunity to everyone else, too?
I missed a few days due to a migraine headache, so you get another glitch today to make up for that.
This sentence needs a comma after work and another after door. You may also add a comma after and if you like, but these days that’s considered unnecessary.
You arrive home from a late night at work, and when you open your bedroom door, you see yourself sleeping.
Yes, friends, you can string more than two simple sentences into a compound sentence. (The Chicago Manual of Style says so.) What’s more, they all need to be punctuated as parts of a compound sentence.
“That’s humans for you. Cut off a limb, and it will live, but leave it without oxygen for five minutes, and it’s done for.”
(“That’s lab-grown humans for you. Give it a headache through careful manipulation of atmospheric pressure, and suddenly its ‘superpowers’ are shut down for days.” Hmm… Wasn’t the ‘careful manipulation of atmospheric pressure’ actually supposed to have the opposite effect?)
The first sentence contains a comma splice. So does the second. I replaced the commas with semicolons because the connection between the first and second parts of the uncorrected sentences seems too close for periods. (If, however, you’re semicolon-phobic, go ahead and use periods; they’re at least better than commas.)
There’s also a typo in the first sentence; guilt has an extra s on the front.
The third sentence shouldn’t have any punctuation other than the period at the end.
No one noticed how guilty he felt; they only saw his guilt. No one saw the pain he was in; they only saw the pain he caused. No one realized he hated himself far more than any hated him.
(Self-centered, much? *rolls eyes* Why is he assuming they don’t know, and why is he assuming he knows exactly how much they hate him, to say it’s less than he hates himself? ‘You have no empathy because you don’t think my feelings are the most important thing!’ Well, boo-fucking-hoo.)
Replacing noticed in the first sentence with realized would improve clarity.
Cant is a real word, and its meaning is nothing like the meaning of can’t. Don’t mistake the two or write one in place of the other. If you mean can not, you must use an apostrophe in the shortened form.
A compound sentence doesn’t have to be just two sentences joined by a conjunction. The second sentence is compound and made up of not two but three shorter sentences, so you need a comma to separate the first from the second and the second from the third.
The part beginning with it’s the app follows logically and smoothly from you’re woken up. There is no abrupt change in direction within the sentence, so an em-dash is incorrect. I used a semicolon, but a period would also work.
Yesterday you found a new app on your phone. It doesn’t open, you can’t delete it, and you don’t know what it is. Tonight, you’re woken by an alert on your phone; it’s the app notifying you of some very specific instructions.
This is still not quite right… Let’s see if (not that there’s any doubt!) it will work better once we tidy up the verb tenses.
Yesterday you found a new app on your phone. It didn’t open, you couldn’t delete it, and you didn’t know what it was. The next night, you were woken by an alert on your phone; it was the app notifying you of some very specific instructions.
If you want to eliminate very from your writing, replace very specific with precise.
The first sentence in the example contains a comma splice (two sentences incorrectly joined by a comma).
The second actual sentence (beginning with As you know) needs a comma after know.
Welcome to Eden Station. As you know, the Earth is about to be destroyed. Please follow the green line to your assigned quarters and enjoy the show.
I don’t like the second sentence — it’s quite clunky — but I don’t see any easy way to fix it, and I don’t feel like rewriting the whole thing for a mere grammar-and-punctuation exercise.