Five Common Grammar Mistakes People Make

Grammar mistake number one: If you are an American writer or want to be published in an American magazine, then the rule is periods and commas always go inside the quotation marks with only a couple of exceptions. (This rule does not apply to any other punctuation marks.)
Wrong: I rode in his "truck".
Correct: I rode in his "truck."
Wrong: We named the dog "Ralph", but he doesn't respond to it.
Correct: We named the dog "Ralph," but he doesn't respond to it.
The exceptions:
In certain scholarly and science disciplines this rule does not apply. The British do not follow this rule, either.
For letters and numbers, periods and commas go outside the quotation marks:
Go to gate "5". However: Go to gate "five."
He can't pronounce "w".
He went to gate "5", but no one was there.
We ought to teach him how to pronounce "w", but it's unknown how.
 
Grammar mistake number two: Me and my boyfriend went to the beach, is incorrect. You wouldn't say, Me went to the beach, so why say, Me and my boyfriend.... A way to correct this is to put the person you did whatever with first. It becomes harder to say, My boyfriend and me went to the beach, because when you say, ...me went to the beach, it won't sound right and you will automatically think, I went to the beach. Then you will say it correctly. My boyfriend and I went to the beach. (Me and (whoever)... is gaining more and more acceptance and may someday be considered proper grammar.)
 
Grammar mistake number three: There is no such word as alot. This may come about in the future since a lot of people use it, but right now, you won't find it in the dictionary. Nor will you find its'. Its is the possessive form of it. It's is the contraction of it is or it has and any other use is wrong.
 
Grammar mistake number four: Never place a comma or period after an explanation point or question mark.
Wrong: He asked, "Can I go, too?".
Wrong: He asked, "Can I go, too?."
Wrong: "Can I go, too?", he asked.
Correct: He asked, "Can I go, too?"
Correct: "Can I go, too?" he asked.
Wrong: "I want to go!", he exclaimed.
Wrong: He exclaimed, "I want to go!".
Correct: "I want to go!" he exclaimed.
Correct: He exclaimed, "I want to go!"
 
Grammar mistake number five: Lie, lay, lain, laid or lied? This one confuses many people. Here's how it breaks down.
lay--laid--laid; to place or to put
I lay my books on my bed today.
I laid my books on my bed yesterday.
I have laid my books on my bed in the past.
lie--lay--lain; to recline or to rest
I lie on my bed today.
I lay on my bed yesterday.
I have lain on my bed in the past.
lie--lied--lied; falsehood
I lie a lot.
I lied a lot yesterday.
I have lied a lot in the past.
Now you can say, "I lied when I said I lay on my bed next to the book I laid on my bed." (Translation: I told a falsehood when I said I crawled on my bed and stretched out next to the book I put on my bed.)

Subjunctive Mood

The subjunctive is a grammatical mood found in many languages. Subjunctive forms of verbs are typically used to express various states of unreality such as wish, emotion, possibility, judgment, opinion, necessity, or action that has not yet occurred – the precise situations in which they are used vary from language to language. The subjunctive is an irrealis mood (one that does not refer directly to what is necessarily real) – it is often contrasted with the indicative, which is a real mood.
Subjunctives occur most often, although not exclusively, in subordinate clauses, particularly that-clauses. Examples of subjunctive use can be found in the English sentences "I suggest that you be careful" and "It is important that he stay by your side." (The corresponding indicative forms of the italic verbs would be are and stays.)

Examples:

I was in your position two years ago. (not in the subjunctive mood: indicative mood)
If I were in your position, I would do the same. (subjunctive mood)

The following verbs often attract the subjunctive mood: ask, command, demand, insist, order, recommend, suggest and wish.

Examples:

I wish it were still in use. (subjunctive mood - "it was" becomes "it were")
The board recommended that the motion be passed immediately. (subjunctive mood - "motion is passed" becomes "motion be passed")
She suggests that Mark work full time from Saturday. (subjunctive mood - "Mark works" becomes "Mark work")  
 

The following adjectives often attract the subjunctive mood: crucial, essential, important, imperative and necessary.

Examples:

It is imperative that the game begin at once. (subjunctive mood - "game begins" becomes "game begin")

Are you in a subjunctive mood? Then you should frame sentences in one of the six following forms.
The subjunctive mood is used in cases in which what is expressed is not necessarily real, as opposed to the indicative case, which is applied to factual statements. The key difference is a change in the form of a given verb: Am or was is supplanted by were, be takes the place of are, or singular active verbs lose their -s or -es endings. In conversation, it is common for speakers to fail to distinguish between the moods, but in careful writing, the distinction must be made.

1. Counter factual
In this subjunctive construction, the writer expresses a notion contrary to fact, such as “If I were you, I’d return it to the store.”
2. Imperative
In this class of the subjunctive mood, commands and demands are expressed: “I demanded that she walk away.”
3. Necessity
This subjunctive form refers to requirement: “It is necessary that she fill out the form first.”
4. Proposition
This category applies to proposals and suggestions: “We proposed that they reconsider the offer.”
5. Supposition
In this form, the writer expresses a possibility: “If I were to accept the position, I’d have to relocate.”
6. Wish
This type of subjunctive form deals with expressions of desire: “I wish that I were able to go back and do it over again.”
The subjunctive case also survives in such idiomatic phrases as “as it were,” “be that as it may,” “be they [one thing or another],” and “would that it were.”