Even in a conversation with a friend you would use the past tenses.

1. 2 is correct, but why ‘such’ a good idea? It seems a little redundant. 2. Either is correct, depending what you mean! 3. Again, either could be correct, depending on context. Eg we have a saying ‘you don’t know what goes on behind closed doors.’ Equally, if I was confused about what was going on, i could say ‘I don’t know what’s happening.’ 4. Neither sounds correct - I’m not sure what you mean to be saying.

B and C are correct.

It’s hummed and harred, (pronounced /hard/), in Uk English.

Qu1. Both are correct. Which you use depends on when you’re speaking - is it while the match is going on? In this case, he isn’t playing. You will hear this during any match commentary: Ronaldo isn’t playing today. After the match, however, you would say Ronaldo didn’t play today. Qu 2 - same answer :)

The only difference is in the subject of the sentences (attack or defence) and therefore the implied emphasis.

Hi. Firstly, I would dispense with the always, in the phrase ‘it always seems probable’. Secondly, I would start the second sentence with a statement: the main function of ... By starting the sentence with the word ‘this’ you are implying that you have introduced the idea in the previous sentence. When you use pronouns, or words like this and that, be sure to ask yourself what you are referring to. Not making this clear is a common fault in the academic writing of even English first language speakers :)