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:
The check routing symbol on that example can't be correct.
That is a large amount of money for such a small bank to lend, so it might be a good idea to demand a confirmed letter of credit, in case the first bank cannot pay.
Our net profit this year must be more than our profit from last year.
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:
Net profit must be achieved before assets are depleted.
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:
You might be surprised to see the decision tree this time next month.
Capital loss may not inhibit this client from investing further a couple of months from now.
'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:
You can't countersign a document if you are under 18 years of age.
That bank deposit can't be from my company.