Here’s a mistake I’m seeing more often: unnecessary question marks. For example:

I asked the manager why the restaurant didn’t offer meatless entrees?  WRONG

That’s a statement, not a question.

Now try this one. Does it need a question mark?

I asked a question.

Obviously it’s a statement. If you read it aloud, you won’t hear your voice go up. What about this?

I asked why the bill was so high.

When you think about it for a moment, it’s just like the previous example – a statement. No question mark.

Read them together, and you’ll hear it:

I asked a question.

I asked why the bill was so high.

For comparison, here’s a true question:

Why is the bill so high?  CORRECT

Let’s try a few more:

I asked Joe to pick me up at 7:30.

I wondered whether he would be on time.

I questioned whether he was trustworthy.

Those are all statements that should end with periods. How did you do?

Now try these (remember, reading them aloud will help):

Will you pick me up at 7:30

Is Joe going to be on time

Is he trustworthy

Those are all questions that should end with question marks.

Will you pick me up at 7:30?  CORRECT

Is Joe going to be on time?  CORRECT

Is he trustworthy?  CORRECT