The modal auxiliary verbs ‘could’, ‘will’ and ‘would’ are often employed in daily usage, but we may see people especially second language learners in English often confused when these choices come to them. Although they are close in meaning and use, they have different natures and expressions.
Natures of ‘could’, ‘will’ and ‘would’
Above natures are found in daily examples and collected in some references. But if we want to look deeper on modal verb, Givón (1993) mentioned that modal verbs are all irrealis operators with a modality concept which indicates speakers’ attitude and their judgment toward the proposition. English modals can be categorized as two different types of judgement including epistemic and deontic aspects. Now, we would try to explain more by using the below situational analysis: If a friend invites us coming to the party, the three below replies are grammatically correct, but it is semantically different.
- I think I could go to your party.
In this sentence, ‘could’ can be interpreted as the nature of ability and probability. However, it can be understood in different senses. The first interpretation is the speaker has the ability to go to the party with the deontic sense which it implies the speaker may be a disabled person and he figured out how to go to the party, so he is able to join it. The second interpretation is the probability with the epistemic sense that showing he is possible to join the party in the coming future. Both are future projecting and in a polite tone.
- If Nancy is there too, I think I would go to your party.
This is a counter-factual sentence by using conditional sentence in irrealis. The first clause ‘If Nancy is there too’ in this sentence shows the speakers’ subjective judgement about preference which is a deontic sense while ‘would’ the second clause is an epistemic sense, showing weaken probability of the speaker possible to join the party in the coming future. It also signals speaker’s willingness and volition.
- I think I will go to your party.
‘Will’ in this sentence can be considered as a future aspect marker and it is an irrealis assertion. Since ‘will’ render the high certainty and high probability that speaker goes to the party, the irrealis is weakly asserted as possible or liklely. The event may come true in a high possibility. Therefore, it is epistemic with a less formal or polite tone.
Since modal verbs involved the concept of modality, even though all sentences especially the present the similar meanings by looking literally, it actually implies different semantic ideas and we have to explore in their natures and two aspects including deontic and epistemic. Different presentation on using modal verbs can render different tone and implication.