Modals of Deduction

When we want to speculate or make deductions about a particular situation we can use the following modal auxiliaries:

• Must, Couldn't, Can't: when we are 99% sure about something.
• May (not), Might (not), Could: when we think something is possible.

These modal auxiliaries can be followed by verbs in the simple present, present continuous, present perfect or present perfect continuous.

Present: It couldn't be that bad!

I think he might be working late today.

Past: Diego may have found out about Frida's affair.

Sorry, I must have been daydreaming.

We usually use couldn't with the present perfect and we can use either couldn't or can't with the simple past.

For extra info, check out this!!!!

Take a look at these presentations about:

• Modals of Deduction
• Modal of Deduction in the past

Grammar Exercises

Now Guys: let's test your knowledge about Modals of Deduction. Log on to this links and you will find them. Leave us message about how you did in the exercises. Good Luck!!!

• Exercise 1
• Exercise 2
• Exercise 3
• Exercise 4