We need to approach modal auxiliary verbs from two directions.  First, there's a long tradition in teaching ESL/EFL/ESOL to work from a list of the individual modals that has a few typical meanings for each of them. For example, will is defined as "future certainty" and would as "past habit" or "conditional." Indeed, you won't have taught ESL/EFL for long before you'll have memorized some of this terminology. Most textbooks include these lists. Such a list would be much more useful for you and your students if you went through and added your own examples based on the kinds of information that would be useful and interesting to your students.  If you decide to use these meanings and list, be sure to modify the examples to meet the particular needs and interests of your class.

Second, we also need to recognize that the modals work together in a systematic way.  When we decide to use one of the modals, we are also deciding not to use the others.  Think of the common question about rules--"Is that a 'should' or a 'must'?" 

(Isn't it interesting to see that we've taken the modals and used them into nouns?)

The question requires that you make a decision between two modals based on the strength of meaning that you think is appropriate--should suggests some flexibility and choice; must is more rigid.   The consequences of not doing a "must" are much more severe than the consequences for not doing a "should."

Think of the common phrase used to turn down an invitation--"I would if I could but I can't....so I won't."  That's what I mean by system.  Playing one word against another; selecting words for just the right level of meaning.

Studies of modal auxiliaries focus on two major subdivisions based on meaning relationships among the words and on their use for communication.  The first of these subsystems involves communication about advice and requests and permission.  The Comprehensive Grammar of the English Language refers to this subsystem as the "intrinsic" system; another term used by other scholars is "root modals."   In this example discussion, the student asks for permission; the advisor responds with a series of modals, moving from the neutrality of can to the strong requirement of must.
 

The second of the major modal systems involves communication about our interpretation of events--our judgments about what we think happened or is happening.  The Student's Grammar calls this subsystem "extrinsic" modality; another name is "epistemic" modals from the word epistemology because these uses reflect our knowledge and our judgment about the accuracy of our knowledge.  When we use a modal for this meaning, we made decisions about what we think we know and how strongly we believe that our knowledge is correct.  In the following example conversation, might implies a lack of certainty; Martha is not sure about her information.  After reading the sign, Maria thinks she knows the answer and uses must. 
 
 

Back in Session 1 in the lecture on examples, I used the following example to show how to contextualize the modals.  Let's look at the example again to understand more about the systematic nature of modals and about the influence of context on their meanings.
 
 

	weaker stronger	Modals Used to Ask/Give Advice A Student Asks Various People the Same Question: What Classes Should I Take This Summer? The following answers show different levels of advice--from weak advice to very strong advice
		Advisor: You can take SLA or Classroom Practices or the Practicum or Materials Development.  They are all offered and at different times on the schedule. Your choice--do what you want to.
		Friend: You should never take more than one course in the summer.
		Graduate Coordinator: You have to take two courses this summer if you want an assistantship. Those are the GSU rules. No exceptions. You must take two courses to get an assistantship--even in the summer.

When someone asks for advice, we can respond at many different levels.  We can give neutral advice about things that are possible (can, may, might); we can give stronger advice based on our own sense of obligations and the "right thing to do" (should); or, we can talk about rules (must).

Notice also that power relationships can influence the use of modal auxiliaries.  Who has the right to give rules?  Who has the right or the right status to give strong advice?  Additionally, the meanings of the modals can change based on cultural values about power relationships.  A person in higher authority in the U.S. might very well use a weaker modal that has a much stronger meaning than implied by its dictionary definition.  What does a teacher mean when she says: "You might study chapter 4 for the exam."  Or, what does a boss mean when she says to a clerk: "You should revise the memo before it is sent."  Literal interpretation of these modals could very well lead to problems for the student who doesn't study chapter 4 or the clerk who decides not to revise the memo.

Eli Hinkel (1995) studied differences in the ways that native speaker undergraduates and ESL students used modals in argumentative writing.  She analyzed the ways that the modals and modal-like words must, have to, ought to, should, and need to were used to express values in essays on assigned topics that she labeled “Academics, Politics, Family, Friendships, Traditions, Patriotism, and Racism.”  She found that native and non-native speakers of English use must, have to, and should in different contexts.  In her conclusion, she provides the following interpretation of her observations:
 
 

As she suggests, this result has numerous implications for the teaching of ESL/EFL grammar and writing—especially for teaching students about persuasive writing. 

• Hinkel mentions the limited usefulness of working on the forms of modal auxiliaries and the importance of having ESL/EFL students learn about the use of these forms in context. 

• She also suggests that students can observe how these modals are used by native speakers as one method for learning more about the value system that lies behind the materials that they are studying in their academic programs. 

In an article by Woods on World Englishes, he comments on the use of "hedging" in academic English.  (I've given the link in the reference section below.)  "Hedging" is when we reduce the strength of a generalization--a kind of appropriate modesty in making academic claims.  Rather than saying "The world is round," we might say something like "Much evidence suggests that the world might better be described as round rather than flat."  It's not that the writer thinks that the world is not round but that the proper style is to present all generalizations in contingent wording.  Look at the following quotation from the sociology textbook that I'm using to find authentic examples.  The writer hedges his generalization first by the use of the adverb perhaps and then by the use of might.  Along with modal auxiliaries, adjectivies and adverbs as "downtoners"--a feature of English that makes it possible for speakers and writers to fit our statements to the style required by particular settings.
 
 

Based on this information and on the details presented in the Longman Student Grammar, what do you see as the teaching issues involved with the modal auxiliaries? I see at least the following:

1. Basics: word order and use in questions and negation and spelling and core meanings.  These basics are not usually terrible problems for students. 

2. Beyond the basics: meaning shifts in different contexts, use in academic settings to downtone generalizations, cultural influences on modal selection and use, the importance of modals in stating values and fine shades of meaning.  These matters of meaning and use in context are major problem areas.  Students need to have study (with authentic examples) to help them learn about how meanings shift in context and about the use of these modal auxiliaries in the kinds of language they need to use. 

Hinkel, E. (1995).  The use of modal verbs as a reflection of cultural values. TESOL  Quarterly 29(2), 325-341.

Wood, Alastair. (April, 1997). International scientific English: Some thoughts on science, language and ownership. Science Tribune.  [http://www.tribunes.com/tribune/art97/wooda.htm#R22] (accessed 12/21/1999).

Please email me your questions and comments.  I look forward to hearing from you and to learning from you in the small group discussion about teaching the modal auxiliaries.