Re: Omitting the word "that".
As far as BrE is concerned, I recall spending a lot of time explaining to incredulous Spaniards that English (as a language) is simply not taught to British children in school. Because of the complexities of the grammar (verb endings etc) in many European languages, for example, children are properly taught to speak their own language. We are not. British children learn to speak their own language through experience, by listening and by repetition.
As a child, I was lucky. My parents and my grandfather were very keen on grammar and on language generally, and all spoke various foreign languages. They helped me more with my essays etc than with any other subject. When I went to secondary school, everyone was obliged to take one extra subject for one year. The choices were psychology, Latin or grammar. There were 180 people in my year. Of those 180, seven of us chose grammar.
My best friend decided to learn to speak French at the age of 42. She attended a beginners' class but was flummoxed at the very first class (as were most of her classmates) when the teacher said "OK, we're going to start by conjugating the verb "etre" and then we will move on to other verbs". My friend had never conjugated a verb in her life, had no idea what the terms "first person singular", "third person plural" etc meant. She did not know the difference between a verb, a noun, an adjective, an adverb or any other grammatical term. The class teacher, who was French, was very surprised that about 80% of the students had no knowledge whatsoever of English grammar. They were not only beginners in French, they were beginners in grammar.
My point is that if you ask the average BrE speaker to explain the construction of a sentence, or ask them if something is grammatically correct or not, they will be unable to answer you. As far as most of them are concerned, if they can understand what you mean, then you've said it correctly.
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.