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:
Net profit must be achieved before assets are depleted.
According to the articles of association, it may be possible that you may sublease your condo.
Jonathan can't be considering that stock deal.
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 accountant must be sure where to put a double entry in our books so everything can balance
Our net profit this year must be more than our profit from last year.
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:
Making consistent bank deposits each month could be the first step towards getting out of debt.
Susan might be able to give the presentation on the articles of association.
'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:
Jonathan can't be considering that stock deal.
You can't countersign a document if you are under 18 years of age.