§ 234. The category of posteriority is the system of two-member opposemes, like shall come – should come, will be writing – would be writing, showing whether an action is posterior with regard to the moment of speech or to some moment in the past.
As we know, a ‘past tense’, verb denotes an action prior to the moment of speech and a ‘future tense’ verb names a posterior action with regard to the moment of speech. When priority or posteriority is expressed in relation to the moment of speech, we call it absolute. But there may be relative priority or posteriority, with regard to some other moment. A form like had written, for instance, expresses an action prior to some moment in the past, i.e. it expresses relative priority. The form should enter expresses posteriority with regard to so íå past moment, i.e. relative posteriority.
The first member, of the opposeme shall enter – should enter has the meaning of ‘absolute posteriority’, and the second member ‘possesses the meaning of ‘relative posteriority’. These two meanings are the particular manifestations of the general meaning of the category, that of ‘posteriority’.
The grammemes represented by should come, would come are traditionally called the future in the past, a name which reflects their meaning of ‘relative posteriority’. But there is no agreement as to the place these grammemes occupy in the system of the English verb.
Some linguists regard them as isolated grammemes, outside the system of morphological categories. Others treat them as some kind of ‘dependent future tense’ and classify them with those ‘finite verb forms’ which depend on the nature of the sentence. A.I.Smirnitsky tries to prove that they are not ‘tense forms’ but ‘mood forms’, since they are homonymous with the so-called ‘conditional mood forms’. Cf. I thought it w o u l d r a i n. I think it w o u l d r a i n if it were not so windy.
In our opinion none of these theories are convincing.
1. The grammemes discussed are not isolated. As shown above they belong to the morphological category of posteriority.
2. They are not «tense forms». In the sentences
I know she will come.
I knew she would come.
I had known she would come.
neither will come – would come, nor knew – had known is a tense opposeme, because the difference between the members of the opposemes is not that of tense. The members of the first opposeme share the meaning of ‘future’ tense, those of the second opposeme – the meaning of ‘past tense’. The only meanings the members of the first opposeme distinguish are those of ‘absolute’ and ‘relative’ posteriority. The members of the second opposeme distinguish only the meanings of ‘perfect’ – ‘non-perfect’ order.
3. The grammernes in question are not ‘mood forms’.
As we know all the grammemes of the subjunctive mood (with the exception of be)are homonymous with those of the indicative mood. So the fact that would rain is used in both moods proves nothing.
The examples produced by A.I.Smirnitsky clearly show the difference between would rain in the sentence I thought it would rain and in the sentence I think it would rain, if it were not so windy. The first would rain is opposed to will rain (I think it will rain) and denotes a real action following some other action in the past (I thought...). In other words, it possesses the meanings of ‘indicative’ mood and ‘relative’ posteriority. The second would rain cannot be opposed to will rain. It denotes an imaginary action simultaneous with or following the moment of speech (I think ...). Hence, it has the meanings of ‘non-perfect’ order and ‘subjunctive mood’.