Depending on the context, the first sentence can suggest that something happened, but is no longer happening. It's easier to see with different verbs: "I have eaten an apple" = Eating an apple is something I did in the past. "I have been eating an apple" = Eating an apple is something I was doing, and am still doing. Of course, adding the time component ("for 10 years") heavily suggests that we're talking about something in the present, but it doesn't guarantee that meaning. For example: "I have lived in London for 10 years - 5 years in 1995, then 5 years in 2005" is a valid sentence. So, in general, the sentences are almost always the same. In most cases they would be interpreted the same. But there is a very small range of constructions where they mean different things.

1) The word 'whoever' is being used as a direct replacement for the person's name. For example: "The purple thingie on the file means that Steve is one of yours" using 'whoever' in this way is very rude/low informal. We can also replace the name with things like "what's-her-name" (for people) or "thingie", "whatsamacallit" (for objects). Your example sentence is gramatically correct, and significantly less impolite. '... and everything' is used to exaggerate the features of an object. For example, if I have a new car, I might explain how it has a sunroof, air conditioning, a back massager and everything. In this case it's obvious that Wilson is a doctor - House is pretending to be impressed by his diagnosis by talking about how good at figuring out symptoms he is. In general, 'doing' is done with illegal drugs. You 'do' cocaine, you 'do' heroine (there are other verbs we might choose to use as well). By House saying he 'did' 1000mg, he is making fun of his own habit of misusing medicine by pretending it is an illegal drug. 2) I'm guessing that it's to do with football formations. Generally, when planning your football team's strategy, you tend to allocate some players to be in the back (defenders), some people in the middle (center), and some people in the front (attackers). A common description of a team's strategy would be "They've chosen to go with three up front" (they have three players attacking). In this case, they're making fun of the fact that they put a tree at the front of the football field, and the word 'tree' sounds like 'three'.

1) No, although when it's not said it's implied. "I really like eating ice cream. On the other hand, I know it's bad for me." "On the one hand, I really like eating ice cream. I know it's bad for me, though." "On the one hand, I could stay up all night watching movies and eating pizza..." 2) Yes. They have slightly different meanings. The first sentence suggests that the language is lost first, and then the culture is lost (because the language is gone). The second sentence suggests that the two things happen at the same time (or the order could depend on the intonation). 3) It makes sense, but it feels a little rigid. The simple present tense suggests certainty - whereas the previous sentences use the conditional 'would'. I might expect to kind such a sentence in a piece of persuasive writing.

All three are usable, and have different meanings. "I really don't know" - 'really' emphasizes the word "don't". The speaker is pointing out that they don't know the fact at all. "I don't really know" - 'really' emphasizes the word 'know'. The speaker might have an idea of what is happening, but isn't certain. "I don't know really" - 'really' acts as a "filler" word. The sentence "I don't know" sounds short and rough/blunt, so it is rounded out by adding 'really', even though it carries no significant meaning. This kind of speech would be fairly common in an informal setting. The overall meaning is essentially the same as the second sentence.

A girl assistant is an assistant who is a girl. The meaning can sometimes vary: for example, a 'car assistant' is probably someone who assists you with cars (not an assistant who is a car). There's no particular reason why 'girl' is used instead of 'female' or 'woman' here. Girl implies the person is younger, (perhaps less than 30 years old).

Sometimes we refer to luxury used in this way as a 'noun modifier'. It helps to view 'luxury goods' as all one word - much as we would things like 'fire extinguisher', 'express train', 'general waste' etc. The main way we can think of them differing is in our expectations. Luxury goods are - by definition - fancy, beautiful and so on. On the other hand, luxurious goods are goods which happen to be luxurious. For example, I might go to a second-hand store to buy things that other people don't want. These goods are definitely not luxury - someone has thrown them away. But they might be luxurious, because they are made from fine materials.

They do indeed have a very similar meaning. I'll try and outline some differences: Postpone: This usually carries the meaning that someone has intentionally decided to do the task later. It suggests that there's a reason for doing it (other than laziness) - maybe it is necessary to wait for something else, or there will be a better opportunity. It is usually used in more formal or business environments. Put off: This suggests that the task should be done now, but the person is choosing to do it later. It's quite likely that the person isn't doing it because they're lazy, but not necessarily true (often a reason would be included). 'Put off' also carries different meanings in different contexts - it can be used to suggest that you grew to dislike an object, or you were persuaded not to do a task. "I'm putting the work off until later because I'm so busy right now" "Seeing him eat like that put me off wanting to eat" (I don't want to eat because he makes a mess when he eats) "I was put off by her bad perfume" (I smelled it and now I feel sick) Procrastinate: Unlike the other terms, this one generally doesn't take an object. We might say: "I have been procrastinating recently", but we wouldn't really say: "I have been procrastinating doing the dishes" In general, procrastinate means that there are some things that should be done, but you are not doing them - the other terms refer to specific things that we should be doing. We can also describe what we are doing instead of the thing we should be doing: "I have been procrastinating by watching TV (instead of cleaning the house)".

I'm far from a high level speaker, so take the answer with a grain of salt: This is the result of the construction ~ㄴ 것 being applied to the verb 증가하다, to create the meaning: 'the action of something increasing' (in the past) The construction '~(으)로' carries the meaning 'through, or by using'. So the full construction: '증가한 것으로' is interpreted as 'through/because of the increase in'. I think this makes the entire sentence translate as roughly: 'A drastic increase in mobile phone shopping customers has arisen from many people becoming smartphone users'