Can/Could? Will/Would? How To Teach Your Students The Difference (A Quick And Simple Summary)

This might just be what your ESL students are asking themselves. With so many modals with small nuances of meaning, things can get confusing very quickly. Two of the biggest sources of confusion come when deciding between can and could or will and would. Is one past? Is one future? Is one polite and the other not? If you suspect your students are confused about the difference between these pairs or modal verbs, here is a quick explanation of their differences.

Here's How You Can Help Your Students with Confusing  Modal Verbs

1. 1

   CAN Expresses an Ability

   Has everyone had an elementary school teacher who answers the question, “Can I go to the bathroom?” with “I don’t know. Can you?” The reason teachers (and plenty of others) respond this way is to emphasize the meaning of can. Can expresses an ability. Something of which a person is capable or is able to do. When used properly, questions with the modal can are inquiring about a person’s physical or mental capabilities. Is this a possible or viable option for them? It is in contrast, therefore, with “may” which asks permission to do a particular action.

   To practice proper use of can with your students, brainstorm a list of special skills a person might have. Your list might include serious items such as play the guitar or order a meal in English. It might also include silly items like rolling your tongue or wiggling your ears. (As you are brainstorming skills, you might want to use the opportunity to introduce some unusual vocabulary to your students.) Once your class has brainstormed as many abilities as they can think of (or until you run out of time) have pairs of students ask one another if they possess any or all of the abilities your class listed.

   • Can you speak Chinese?
   • Yes, I can. No, I can’t.
   • Can you ride a unicycle?
   • Yes, I can. No, I can’t.
2. 2

   COULD Expresses a Possibility

   Whereas can asks about the ability to do something, could asks about the possibility of something. Could you do something? Is it possible for you to do something? Often these possibilities are part of a polite request. Could you pass the salt? Most often, a person would be physically capable of passing the salt. Using could in your question makes it a request rather than an inquiry about a physical ability, and polite one as well. Could you come early and help me set up? Could you stop calling so late? Though grammatically questions, they are rhetorical; the speaker does not expect an answer to his question since it is a request.

   To practice the use of could, set up a role play for your students. One person is a house guest who has over stayed his welcome but has no other place to go. The other is the homeowner who wants his guest to leave. Have students perform the role play one pair at a time and try to come to a compromise that will satisfy both parties. As they do the role play, they should concentrate on using could to ask questions of possibility as they negotiate.

3. 3

   WILL Expresses Plans for a Future Event

   Even the most elementary of ESL students knows that will is used to express future plans. It is the key to correct formation of the simple future tense. When it’s used as a modal verb, will expresses plans for a future event. Will you finish that project this week? (Are you planning on finishing the project this week?) Will you call your sister? (Is it in your plans to call your sister?)

   One of the easiest ways to practice using will is to talk about your daily schedule. Have students share with a partner the things that they will do tomorrow, next week, and next month. Remember the plans they share should be exactly that – plans. If an event is tentative or just in the idea process, do not use will to share it.

4. 4

   WOULD Expresses Conditional Results and Polite Requests

   In some ways, would is similar to could. It is used to make polite requests. Would you finish the project this week? (Please finish the project this week. I want you to finish it.) Would you call your sister? (I am asking you to call your sister.) Would expresses a little bit more certainty and is a little bit stronger than could when making requests.

   To practice using would for polite requests, set up a role play for groups of four to six students. For the role play, students will pretend to be at a business lunch. Each person should have a unique goal for the group’s project – designing a brand new theme park. As the group makes their plans for the park, they should ask their coworkers to compromise using would questions. (Would you be willing to include a roller coaster? Would the people like a merry-go-round?)

   Would is also used for future unreal conditionals, also known as second conditionals. In this structure, a condition is expressed in an if-clause (the verb tense is in the simple past in the if-clause) and the result clause is expressed with would + main verb. These future events should be unlikely or even impossible. For example, if I won the lottery, I would buy a new house. (It is extremely unlikely that I will win the lottery.)

   To practice conditional structures using would, have groups of two to three students make a list of ten questions about unlikely or impossible futures for their fellow classmates. (What would you do if…) Once groups are finished writing their questions, have two groups combine and ask each other the questions they came up with. Encourage creativity in the questions as well as the answers.

Modal verbs might be confusing for your students at first, but with practice and perseverance, they will become comfortable and fluent using them. Take the time to walk your students through the different meanings, answer questions as they come up, and be patient with your explanations. All the work will pay off in the end when your students are clear and precise in the modal verbs they use.

Do your students struggle with any other modal verb confusion?

What do you do to help them clear it up?