Correct grammar is about knowing where words and their parts belong in sentences. It can include possessing knowledge of word categories, inflections, and how they operate and relate to other words within a sentence. Good grammar is fundamentally important to the way we communicate. If we lack knowledge about grammar, our communication suffers. This can produce flow-on effects into our lives and careers. Often, it doesn’t matter how intelligent or knowledgeable you are; if you lack the necessary grammar skills, you can lose credibility. Some Grammar Basics There are some basic aspects of grammar. Knowing these will improve your writing. Some of the basics of grammar include: Nouns. These words are "things" — such as people, places, and ideas. In the sentence, "The cat sits on the mat", the nouns are "cat" and "mat". Verbs. These words are "doing words" because they convey action — "run", "catch", "sing" are all examples of verbs. In the sentence, "The cat sits on the mat", the verb is "sits" because "sitting" is what the cat is doing. Adjectives. Adjectives are "describing words" because they describe things — for example, a thing might be "exciting", "heavy", or "awkward". Adjectives add something extra to the sentence. In the sentence, "The black cat sits on the new mat", the adjectives are "black" and "new" since "black" is describing the "cat" and "new" is describing the "mat". Adverbs. Like adjectives, adverbs add something extra to a sentence. Adverbs describe verbs (and adjectives and other adverbs). For example, you might run quickly, catch awkwardly, or sing badly. In the sentence, "The black cat sits quietly on the new mat", the adverb is "quietly" since it is describing how the "cat" is "sitting". Subjects. The "subject" of a sentence is the thing that does the verb; in other words, the thing that conducts the action. In the sentence, "The cat sits on the mat", the subject is "The cat" because the cat is doing the action of "sitting". Objects. The object is the thing that has the verb or action done to it. In the sentence, "The cat sits on the mat", the object is "the mat" because the mat is the thing that is having the verb being done to it — it is the thing being sat on. Active voice and passive voice. "Active voice" and "passive voice" basically refers to the order in which you have placed the subject, verb, and object. The active voice goes: "subject, verb, object"; but the passive voice goes: "object, verb, subject". The sentence, "The cat sits on the mat" is in the active voice because the sentence is in the form of "subject ("the cat"), verb ("sits"), and mat ("object")." Put in the passive voice, the sentence becomes "The mat is being sat on by the cat". Clear writing usually comes from writing in the active voice. This is because the active voice usually conveys your point more quickly than the passive voice and prevents ambiguity by making it clear who did what to whom. The difference between "that" and "which". There is a growing trend toward keeping a strict distinction between the words "that" and "which". The distinction is best explained using an example. Compare these sentences: "I like the cat that is sitting on the mat" versus "I like the cat, which is sitting on the mat". In the first sentence, the word "that" explains that I am looking at several cats; but, of all these cats, the cat I like is the cat that is sitting on the mat. The word "that" tells you that "sitting on the mat" is essential to my pointing out the cat I like. In the second sentence, the word "which" explains that I am looking at only one cat, which, by the way, happens to be sitting on the mat. Here, the words following "which" add an extra bit of information that is not necessary to my explaining the cat I like. If you support this distinction between "that" and "which", you would not write "I like the cat which is sitting on the mat" or "I like the cat, that is sitting on the mat". Keeping the distinction is important because the distinction, more often than not, prevents ambiguity (though there are occasions where ambiguity occurs even while keeping the distinction). Here are some more examples to think about. What is the difference between: "Buy me the milk that is high in fat" versus "Buy me the milk, which is high in fat"; "I visited the house that Jack built" versus "I visited the house, which Jack built"; "I like the primary school books that are easy to read" versus "I like the primary school books, which are easy to read". This is just a small selection of the basic "rules" of grammar. Improve your writing style Writing Better English: Selected Resources English Grammar Mistakes Why Is Good Writing Important? How to Write Well Parts of Speech Powerful Words When to Use the Apostrophe Basics of Punctuation How to Write for Different Audiences Writing Style When to Use a Comma Good Writing