Grammar and Mechanics Gripe

I get so tired of how often these days people don't follow grammar rules or they don't understand certain rules of mechanics. It makes me wonder where the schools are failing because my 7th grade grammar teacher did not give us room to fail that subject! She pounded that grammar and those mechanics rules into our heads so hard I can still recite some of it in my sleep 18 years later!

Here are some common mistakes that I often see:

1. People adding an apostrophe before an "s" to make a word plural. This one really irritates me. Every time I see it, I want to write to that person and ask them if they ever learned this rule.

Here is an example:
We were looking for house's yesterday.

It should read:
We were looking for houses yesterday.

When you need to make something plural, the general rule is that you add an "s". You don't add an apostrophe. Apostrophes are used to show possession, not pluralization! (or I guess some people would write that as...Apostrophe's are used to show possession, not pluralization)

2. Another one:
People using "there" or "their" instead of "they're"; "your" instead of "you're" or vice versa.

Example:
There our good friends.

Should read:
They're our good friends.

"They're" and "you're" are contractions for "they are" and "you are". If you're trying to say something belongs to someone, you can use "their" or "your". "There" refers to a place, such as "I put the book over there."

Those are the two that have been popping up a lot lately. I realize that the mistake a lot of people make is that they're (as in "they are") in a hurry, so they just type. I've even made similar mistakes (although, not usually with the plural rule, that seems so elementary to me), but I usually go back and double check my work before posting a question on a message board or an entry on a blog. Sometimes I still get it wrong, but at least I try to get it right. And at least I know all the rules--Mrs. Gorman taught me well!