What Is Probably True
Modal Verbs of Probability - Present
Modal verbs of probability express an opinion based on what a speaker knows about a situation at the moment of speaking. The following forms are used to speak about present situations.
Example:
We must be interested in laws and practices.
Paul can't be about to leave the sector.
Susan might be able to attend on a scholarship.
Present Forms
'Must' plus the verb expresses the idea that you are almost 100% sure of your opinion about a given situation.
Subject + must + base form of verb + objects
Example:
The lead agencies must be responsible for implementation.
Graham must be trained in comedy.
Use 'might' or 'could' to express an opinion that you think has a good possibility of being true.
Subject + might / could + base form of verb + objects
Example:
Susan might be able to attend on a scholarship.
John might be involved in a scientific evaluation.
'Can't' plus the verb expresses the idea that you are almost 100% sure that something is not true.
Subject + can't + base form of verb + objects
Example:
Shannon can't be planning to attend the hearing without legal assistance.
Craig can't be serious when he denies that there are multiple learning styles.