Notional parts of speech have grammatical categories. The grammatical category is a unity of a grammatical meaning and grammatical form. Grammatical meaning is a generalized meaning, often belonging to the level of logic.
For example, all the language forms having the meaning of time are united into the category of tense. All the language forms with a quantative meaning are united into the category of number. Language forms expressing sex distinctions are united into the category of gender.
The grammatical form of category is expressed through the paradigm (a word-changing pattern within one and the same category)
E.g. comes come
Will come would come
Of all notional parts of speech the verb has the greatest number of grammatical categories. In few cases they are built synthetically (speaks, does, helped, asked). In the majority of cases analytical ways are dominating. In verbal grammar at present one can feel strong influence of American E. on British E. in AE some irregular verbs began to turn into regular ones (learnt – learned; smelt – smelled, knelt - kneeled). From AE this tendency penetrated into BE. A similar phenomenon happened in the use of the Subjunctive mood. In modern E. there are cases when the synthetic and analytic forms of the Subjunctive are synonymous: ‘I demandanalytic he should come – I demand he comesynthetic’. The synthetic form is much older. It originated in the period of OE. At the beginning of the 17th century it was brought to America by the first colonists. Later the analytic form developed in Britain and became more popular than the synthetic one, but in the 20th century when the political and economic ties between the USA and Britain increased the synthetic form began to return into BE.
AE and BE differ in use of the verb have. In BE there are 2 kinds of rules regulating its usage. In the meaning ‘to possess’ the verb to have doesn’t use the auxiliary do (Have you a family? – I haven’t a family). But if the verb is used in the combination V+N (to have a rest, to have a smoke) or if it used in the modal meaning (to have to + inf.) the auxiliary do should be used in negations: ‘When do you have your E. classes? – I didn’t have to wait long’. In AE there is only 1 universal rule when the auxiliary do with the verb to have is used in absolutely all the cases: Do you have classes? , Do you have a brother? In BE instead the verb to have is used in the analytical combination have got in the meaning to have. It is very colloquial form: I’ve got to go there = I have to go there = I got to go there.
In AE the auxiliary shall/should expressing Future tense are caused out by will and would. This usage has become common in BE, too.
In modern E. the verb to get in the form ‘got’ can be used in the causative meaning (I got to do it = I have to do it). Or it’s used to derive passive constructions (She got expelled from the university = She was expelled…).
Now this verb is developed in a new universal auxiliary used for various purposes and sometimes its tense form does not correspond to the meaning related by it (I got it = I have it). I have got to do it = I have to do it.
When a combination ‘I’ve got to do it’ loses the verb ‘have’, the remaining phrase ‘got to do it’ still refers to the Present. Summarizing the use of the verbs ‘to have’ and ‘to get’ we see that the tendency of the unification of their usage in modern E. and the analytic combinations of the verb ‘to have’ are more preferable than its usage in a single form. The modern E. verb in some of its forms illustrates a kind of compromise between synthesis and analysis: He has come – I have come. Both forms are analytical but within these analytical forms there’s an opposition between the auxiliary, which distinguishes a person with the help of inflexions. The same holds true in the combination ‘don’t speak’ and ‘doesn’t speak’. The second form makes only the 3rd person. In general the changes taking place in the verbal system show preference in the use of analytical combinations, they show a tendency of the unification of the paradigms of the word-changing of the verb.