Personally, I use: Quite often, people underestimate how difficult the task is. It just feels more natural to me. I'm from the US.

Great question, Florrie. Both “join” and “join in” can refer to activities, but there is a difference in how we use them. Join usually means becoming part of a group, event, or organized activity. For example: “I joined a photography club.” “Would you like to join us for dinner?” “We joined a guided tour of the city.” “The students joined a school tour.” In the last example, “join a school tour” is correct and natural because the students are becoming part of an organized group or event. Join in emphasizes participating in an activity that is taking place, often alongside other people. For example: “Everyone was singing, so I decided to join in.” “The children joined in the game.” “She joined in the conversation.” “We joined in the celebrations.” The important distinction is that “join” focuses on becoming part of something, while “join in” focuses on actively participating in what people are doing. So, although a school tour is an activity, we would normally say “join a school tour” because we are talking about becoming part of the tour group. You could also say “take part in a school tour” or “go on a school tour.” The rule you learned is a useful starting point, but it is not absolute. We can use “join” for organized activities as well as groups. I hope that helps.

Yes. Some of your alternatives are perfectly acceptable, even though they do not match the answer key. For the first sentence: “If they offered you the job, would you accept?” Your version: “Should they offer you the job, would you accept?” This is grammatically possible, but there is a slight difference. “Should they offer you the job” means something like “If they happen to offer you the job” or “If they should offer you the job.” It sounds more formal and can make the possibility seem somewhat more uncertain. The original sentence uses the standard second conditional and presents the job offer as a hypothetical situation. For the second sentence: “The management insisted on our/us wearing dark suits to the meeting.” Your version: “The management insisted that we wear dark suits to the meeting.” This is completely correct. “The management insisted that we should wear dark suits to the meeting” is also correct, particularly in British English. After “insist,” we can use “insist on” followed by a noun or an ing form, or we can use “insist that” followed by a clause. So your answer is grammatically correct even though it uses a different structure from the answer key. For the third sentence: “I’d rather the children didn’t turn on the television without permission.” This is the normal choice. “I’d rather the children wouldn’t turn on the television without permission” is possible in some contexts, but it has a different feeling. “Wouldn’t” can suggest frustration about repeated or deliberate behavior. It can sound as though the children keep doing this and you wish they would stop. For example: “I wish he wouldn’t interrupt me.” This suggests that interrupting is a behavior that bothers the speaker. With “I’d rather,” however, “didn’t” is generally the safer and more natural choice when simply stating what you prefer someone not to do. So in an exercise like this, I would choose: “I’d rather the children didn’t turn on the television without permission.”

We also call it "the pointer finger" among natives in the US. But I can't speak for everyone.

Great observations. Yes, I think your intuition is quite accurate. “Anticipate” is neutral in the sense that what you anticipate can be positive, negative, or neither. However, the word often has a slightly more thoughtful, measured, or formal feeling than “look forward to.” “I’m really looking forward to the trip” expresses your feelings about the trip. It clearly tells me that you're excited or happy about it. “I’m anticipating a wonderful trip” focuses more on your expectation of what the trip will be like. It is positive, but it doesn't express your excitement as directly. That is probably the emotional distance you are noticing. The same distinction appears in your other examples. “We anticipate further changes.” “We anticipate strong growth.” “We anticipate some difficulties.” In these sentences, “anticipate” sounds like a considered expectation based on what the speaker knows or believes. This is one reason it is common in professional, analytical, and formal contexts. There is another useful nuance. “Anticipate” can sometimes suggest not only expecting something but also thinking ahead to it or preparing for it. For example: “We anticipated some delays, so we left early.” Here, “anticipated” suggests that the speakers expected the delays and took them into consideration beforehand. In a very personal and enthusiastic context, “anticipate” is possible, but I would usually choose “look forward to” if I specifically wanted to communicate excitement. “I’m really looking forward to seeing you again” sounds warm and personal. “I anticipate seeing you again” sounds unusually formal and doesn't naturally communicate the same warmth. So your feeling of “emotional detachment” is not simply a non-native misunderstanding. I'd describe it more precisely as a difference in focus. “Look forward to” primarily expresses a positive emotional attitude toward a future event, while “anticipate” primarily expresses a mental orientation toward something expected in the future.

I've never heard "fed up of" but I'm a US native. I see that Jannette did some research for you. It makes sense that in some English speaking countries, it may be used. That happens a lot in English. In my region of the US, we use plenty of non-standard and grammatically incorrect phrasing that confuses learners. It also clearly identifies from which part of the country we grew up or spent most of our time. "Fed up with" is definitely more natural and more widely understood.

Dear diary, Today was quite a good day. After I woke up, I had my usual coffee. I know I should change my routine from time to time, but I really can’t give up my morning cup of coffee. However, I managed to replace my after-lunch coffee with a mug of green tea. Are you glad? Does this prove I have enough willpower? I’m joking… Do you remember the project I had been working on? I finished it last week and delivered the file. Guess what? My boss was super happy! We will put the plan into action very soon. Now I have to go. I’ll write to you soon! John Notes for the student “Change my routine from time to time” does not need a comma before “from time to time.” “My morning cup of coffee” is the natural expression. We do not normally say “my morning’s cup of coffee.” “My after-lunch coffee” sounds more natural here because you are talking about the coffee you usually have after lunch. “I finished it last week and delivered the file” is more natural than using the past perfect. The time expression “last week” makes the sequence clear, so the simple past works well. “Put the plan into action” sounds more natural here than “enact the plan.” We usually use “enact” for things such as official rules or formal measures.

In some languages, I know it's common to say arm for the whole part that extends from the shoulder to the fingertips. Personally, when I hear 'arm' I only think of the part that extends from the shoulder down to the wrist. In everyday English, “arm” can have two meanings, which is probably why this is confusing. Strictly speaking, the arm is the part from your shoulder to your wrist. The part from the elbow to the wrist is the “forearm,” and the part from the wrist to the fingertips is the “hand.” However, in everyday conversation, we often use “arm” to mean the whole limb, including the hand. For example, “Raise your arm” normally means raising your whole arm and hand. If you need to be anatomically precise, the whole thing from the shoulder to the fingertips can be called the “upper limb,” but this is mainly a medical or technical term. So, in normal conversation, it is completely natural to think of your “arm” as including your hand, even though anatomically the hand is a separate part. I know it's confusing but I hope that helps.