Grammatical categories Grammatical category refers to a set of specific syntactic properties of words that can cause those words and/or other related words to change in form for grammatical reasons (ensuring agreement between words).
For example, the word "boy" is a noun. Nouns have a grammatical category called "number". The values of number are singular (one) and plural (two or more). The boy is playing. The boys are playing. In the above example, the "number" of "boy" influences the form of boy, and also influences the form of a related word (be). "Number" is a "grammatical category".
English has over twenty grammatical categories .The most common ones for English learners are: number, definiteness, tense and aspect, case, person, gender and mood.
Furthermore, we can add some others to communicative grammatical categories: Expressing hypothetical meaning Ways of reporting speech
Hypothetical situations are situations that we imagine. There are specific English grammar structures, phrases and forms to express hypothetical situations. .They would invest in R & D if they had the capital. - Conditional Form If only we had enough time to take a vacation. - Partial conditional form / set phrase 'if only' It's time we improved our sales. - Set phrase 'it's time' I wish he lived here. - Verb 'wish' to express a desire
English uses conditional forms to express hypothetical situations.
If they have time, they will come to the meeting. They would invest in R & D if they had the capital. If Jack had taken the job, he wouldn’t have been satisfied.
If Only
If only’ takes the same verb forms as ‘wish’. This form is used as a means of stressing the importance of the wish or hypothetical situation. The form is often also used with an exclamation point. If only there were more job opportunities! If only Mary could work for us. If only our friends had time to take a vacation with us in Hawaii.