10. When talking about ideas, the phrase is flesh out, not flush out. It comes from the idea of taking an idea and "putting flesh on it." Kinda gross, but there you have it.
9. Nothing is "really unique" or "especially unique." By definition something is unique or it's not unique.
8. There are no Cs in the word supersede.
7. You have several brothers-in-law, not brother-in-laws. Same with sisters, fathers, and mothers.
6. In the same vein, they are courts-martial, not court-martials.
5. If there are only two options, you wouldn't say, "the other alternative" because it's redundant.
4. When you are writing about the 1990s, you don't add the apostrophe, it's just the S.
3. Guarantee is a verb; guaranty is a noun.
2. Unless your particular profession requires otherwise, only use one space after a sentence. Using two spaces is a holdover from typewriter days. I have to use two spaces in my day job, and one in my personal writing. It gets confusing. I know the over-30 crowd is screaming, "That's not what I learned!" The convention has changed.
1. The Capitol is a building that is in the capital of the US.