Placement test part 2 1.2 In some countries it is dark all the time in winter. – I should say that in the test that I took there are only 3 variants of answer and the 4th is ‘I don’t know’ ))) When you use a language for spontaneous communication you don’t think of good grammar and you have no time to think. But when you take a test you want to show as a good result as you can so you make mistakes where usually you feel confident. It’s not the case with this example, my answer is correct , but I wanted to explain it to myself because one was the variants is ‘there is’. ‘Dark’ is an adjective, not a noun or gerund. In the sentence ‘In some countries… dark all the time in winter’ we need a subject. So ‘it’ is the subject and ‘is dark’ is the predicate. And of course, ‘it is dark’ – is a collocation that we should remember and use. 1.3 In hot countries people wear light clothes to keep cool. Here I made a mistake choosing ‘for keeping’. What the CambridgeDictionary(CD) says is: We don’t use for + -ing to express our purpose or intention. We use to + infinitive: We’re going to Lisbon to visit my aunt. He’s now studying to be a doctor. You don’t need to bring anything. There’ll be sandwiches to eat and juice to drink. Somebody answered the same question in that way: the infinitive form (to keep cool) is more commonly used to indicate purpose, i.e., to answer the question "Why?" or "For what purpose?" -- They wear light clothes. For what purpose do they wear light clothes? (Why do they wear light clothes?)- To keep cool. They wear light clothes to keep cool. -- They are saving money.- For what purpose are they saving money? (Why are they saving money?)- To go to college. They are saving money to go to college. -- The chicken crossed the road.- Why did the chicken cross the road? (Children's riddle.)- To get to the other side! The chicken crossed the road to get to the other side! Another girl offered the following variant: In hot countries people wear light clothes to keep cool (themselves) but In hot countries people use fridge for keeping drinks cool. As for me I’m not sure that I could understand all the slight differences that’s why I prefer remembering it as a collocation: to keep cool, to keep warm like in another example from CD: Close the door to keep the room warm.