Erika, to answer your question - yes, we do say 'Cut me some slack'. It's an image to do with ropes - for example when you are sailing or climbing. The adjective 'slack' means 'loose' - the opposite of 'tight'.  A rope which is slack is held loosely, with plenty of spare rope between the two people who are holding it. So if you ask someone to cut you some slack (don't worry about the actual phrasing here, which is quite idiomatic) you're basically saying 'Come on, give me a bit more rope - don't pull it so tight'. This means : don't be so harsh on me, be a bit more relaxed, give me some more time, don't apply the rules so strictly, and so on. An employee who's been having problems at home might hope that his boss will  'cut him some slack' for a while. I hope that helps.

Hi Haruka!

You can say both:

The company I work for isn't doing <em>so</em> well this year.

The company I work for isn't doing <em>very</em> well this year.

They mean the same thing. Also, they can both mean in comparison to previous years or just in a more general sense. Usually when a company is underperforming according to your, or somebody else's expectations it will be stated in the sentence.

E.g. Tesco's profits are down a lot more than I thought they would be. 

Hi again GIO!

Number #2 and #3 are about prepositions. Prepositions are super-weird because there are often no rules to help you choose the appropriate one. This just goes to show you that "rules" did not create language. Like any social skill, you just see or hear what other people do, then you do the same. That, in fact, is the simple way that all language has always been learned; but those thick textbooks never tell you the simple truth. However, you can't be lazy to do that simple learning. Because there are few rules for prepositions, learning to use the right prepositions requires wide and deep exposure to reading and listening. That is the best and only way.

In #1, "let's get this straight" refers to something preceding, which is unclear in some way, and the speaker is trying to find something out to explain the unclear situation. Perhaps it's easier to understand the meaning if they said "let's get this clear" (or, let's get the clear and true facts or version); however the phrase "let's get this straight" is more often used; and also more often used perhaps in a perplexed or annoyed tone.

TEACHER: You haven't finished your homework?

STUDENT: My dog ate my homework.

TEACHER: Let's get this straight: your dog was so hungry that it ate your homework instead of its own food?!!

Hey Gio, the word "into" is implicit in the word "enter".

Just look at the definition of "enter": 1. come or go into (a place).

So, "she entered the room" makes perfect sense. It literally means: "she went into the room".

I often hear "cut me some slack" in movies. Is is the same as "give me a break?" Do people actually say this in real life conversations? How informal is it? What's a slack and how can it be cut??? :)