"Don't smile" - моя любимая часть. Я хотел бы знать, включается ли в русскоязычных учебниках английского языка указание «улыбайтесь почаще»?

"As" and "like" are both ok, but I would prefer "like." "As" feels a little too formal. But I would change your sentence to "If you felt like I feel, you wouldn't talk like that." I would change "feel" to "felt" because it's in a counterfactual if clause. Counterfactual if clauses use the past subjunctive.

A "region" is always large, while an "area" can be small or large. You can say, for example, "people in the northern region of the country all wear furry hats," but you could also say "people in the northern area of the country all wear furry hats." On the other hand, you can say "I try to always keep this area of my house clean," while you can't say *"I try to always keep this region of my house clean."

1. "very" here means "same", "the one we're talking about now." Another example: "Three people were killed in the very room you're standing in now." (It doesn't mean "center". I think the other poster was thinking of the expression "the very center of" which means "exactly in the center.") 2. It's the past subjunctive. The subjunctive is used because it's a hypothetical situation. All "to be" forms become "were" in the past subjunctive. "Were I to leave a note", "Were he to leave a note", "were they to leave a note." etc. 3. They continue to go to church. It implies the current generation no longer goes to church. 4. It's simply a continuation of the past tense of the sentence. 5. It's the subjunctive, again. Past tense is usually used with "what if" questions. For example, "what if you saw a talking dog?" 6. The article goes with "lack", not with "love." Lack is a noun.

"Does not pay" means that something does not work out, that it is not worth doing. The most common usage is in the phrase "crime does not pay." The meaning of this phrase is that it is not worth it to be a criminal because the consequences of being caught are worse than the potential benefits. In this case, it is saying that there is no reason to behave badly.