Grammatical mistakes plague the English language- a language which makes little sense to start with, being based on perversions of other languages, so it could really do with not being made worse. If you have any regard for my sanity, please consider my list of the top five grammatical abuses:
1. Photo's
NO. NO NO NO NO NO. The word "photos" does not need an apostrophe, as it is not possessive! Unless your photos own something, they do not get an apostrophe. Plurals of words do not deserve apostrophes.

2. You're and your.
Much to the surprise of the grammatically uneducated, there are actually two very different words. "Your" means "belonging to you", and "you're" means "you are". This may seem strange as the possessive "your" is not endowed with an apostrophe, however this is just one of those peculiarities of the English language which one must be familiar with.

3. Babys
It pained me to write what should be "babies" as "babys", it really did. If there is a Y on the end of a word, in the vast majority of cases, it becomes -IES for plurals. If you have any questions regarding this, you may want to consider re-taking grade two English.

4. Capitalisation Of Prepositions And Conjunctions In Titles
I don't know exactly why, but you just don't do it. It's one of those things that you're just born knowing- well, some of us are, in any case.

5. And finally, accusing sentences starting with"and" or "but" of being grammatically flawed.
They're not. It's actually quite acceptable, in modern literature at least, to start sentence with "and" or "but". Yes, it is a grammatical mistake in, say, most conversations, especially according to old people. However, it is not erroneous to do this is literary works, such as to add emphasis- a writer's creative license overrides the normal rules of grammar!

I really hope there is no bad grammar in the blog post. On the other hand, hypocrisy is okay when I do it.