The apostrophe indicates where letters have been removed from the original words to make the contraction.
So, if you change "do not" into "don't", you have removed the O between the n and the T, so you put the apostrophe in to indicate the missing letter. You only put one apostrophe even if more than one letter has been removed.
No. A spider is a spider and an apostrophe is an apostrophe.
you've is the apostrophe of you have
The apostrophe for "they had" is "they'd".
No, your doesn't have an apostrophe. You're, however, does have an apostrophe because it's a contraction for you and are.
This is an apostrophe.( ' )
An apostrophe is not required.
there is no apostrophe
you dont use an apostrophe in will not
Can't is cannot with an apostrophe.
Shall not with an apostrophe is shan't.
No, taste doesn't have an apostrophe.
"Believes" does not have an apostrophe. It is the plural form of "belief."