Traditionally, two, but I find using just one okay too.
When you are beginning a list of irregular items
Typically, the semicolon implies " and" and therefore using and after a semicolon is redundant.
No, you do not capitalize after using a semicolon unless it is the start of a new sentence or a proper noun. The word following the semicolon should be lowercase unless it meets the criteria for capitalization.
comma in front of therefore; semi colon in back of therefore
For closely related phrases, you can use a semicolon. You may place the semicolon between two independent clauses (an independent clause is a phrase that can be a grammatically correct sentence all by itself.) For example: I love to eat pretzels; salty foods are my favorite. A colon is used in the same way. For example: The fans were cheering very loudly: the Yankees had won.
When using a semicolon you put one space after the semicolon.
After a semicolon, there is never more than one space. Spacing after colons (and periods) depends on the style guidelines you're using. Some call for one space, others for two. The most important thing, however, is to be consistent. Use the same spacing after colons as you do after periods throughout the entire document.
If your sentence requires a semicolon, you may, indeed, end up using it after a parenthetical.
When you are beginning a list of irregular items
I was taught it was two. A good way to remember this is by counting the dots on it. The colon has two so it has two spaces. A semi colon has only one dot, and it has only one space after it. But this only applies when the name of the punctuation has the word "colon" in it, as when you are counting the dots in a period, you only see one, but after a period, you usually put two spaces unless you are using a wesite address or something of that sort.
A semi colon is this sign here ";". It is used in a sentence for adding an extra piece of information at the end, for when a comma will not suffice. For example: Today, it rained; I played with the cat indoors.
Typically, the semicolon implies " and" and therefore using and after a semicolon is redundant.
No, you do not capitalize after using a semicolon unless it is the start of a new sentence or a proper noun. The word following the semicolon should be lowercase unless it meets the criteria for capitalization.
comma in front of therefore; semi colon in back of therefore
If you have two independent clauses that you don't want to isolate into separate sentences, put a semicolon between them.
Yes, that is one of the most common uses of a semicolon. If there is a conjunction joining the clauses, however, you should use a comma instead of a semicolon.
Using a coordinating conjunction (e.g., and, but, or) to combine two independent clauses. Using a semicolon to connect two closely related independent clauses.