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:
Craig can't be relying on temps to work the stockroom.
He must be trying to organize a union.
The manager might be able to set up an email warning when stock levels run low
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:
He must be trying to organize a union.
Peter must be calling human resources.
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:
The manager might be able to set up an email warning when stock levels run low
Bob Porter might be able reduce operating inventory and costs by employing new management techniques.
'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:
Craig can't be relying on temps to work the stockroom.
The manufacturer can't be shipping the storage containers tomorrow.