Common Mistakes

One of the
Remember that "one of the" is followed by the plural form of noun but singular form verb. This is because you are talking about one of the many issues.
Examples:
In phrases like "Vanilla is one of the few flavors that appeals to me," use the singular form for the verb "appeals" because its subject is "one," not "flavors."

Rose is one of the few flowers that not only smells nice but also looks nice. (looks not look)
 

One of the sad things is that my brother isn't around to see it. (is not are)

Into and in to

"Into" is a preposition which often answers the question, "where", how long"
Examples:
Tom and Becky had gone far into the cave before they realized they were lost.

He went into the army.

The snow lingered on the ground well into April.
Two into six is three.

In other instances where the words "in" and "to" just happen to find themselves neighbors, they must remain separate words.
Examples: Rachel dived back in to rescue the struggling boy.
Here "to" belongs with "rescue" and means "in order to," not "where." (If the phrase had been "dived back into the water," "into" would be required.)

Sometimes "into" means "deeply interested or involved in"
Example: Kevin is into baseball cards.

Idioms

 Monday morning quarterbacking: Means giving suggestions on how to do the things that have already been done. Football games are played on Sunday nights. Monday morning, the fans discuss on how the game should have been played by the quarterbacks to win the game.

Example:
Kerry: I would never have waged a war against  Iraq because there are no weapons of mass destruction.

In reality, only after we went into war against Iraq, we came to know that there are no weapons of mass destruction. Kerry didn't tell us what he would have done without that information. This type of criticism is called Monday morning quarterbacking.

Backseat driving: Giving too much unwanted advice.
This idiom comes from the habit many people have of giving too much advice (unwanted advice) to the driver of an automobile from the backseat. This idiom means 'someone who watches and criticizes but not really in charge of the situation'

Example:
Anna did a lot of backseat driving on telling me how to decorate my house.

Pull the wool over one's eyes: "to deceive". "Wool" refers to a powdered wig, such as men used to wear or what the judges in UK wear. Pulling down the wool wig would temporarily blind the person wearing it.

Example: I haven't finished my assignment yet Do you think you can pull the wool over our teacher's eyes by talking about his daughter's sickness? I can finish by then.