Consider the following sentences:
It will snow tomorrow.
It should snow tomorrow.
It may snow tomorrow.
Which sentence expresses the highest level of certainty? If you said the sentence that uses the word “will,” you are correct. Which sentence expresses the lowest level of confidence? That’s right, the sentence that uses the word “may.” The words “will,” “should,” and “may” are all examples of modal auxiliaries. These can cause a lot of problems for English language learners because they are different from other auxiliary verbs and regular verbs.