Teach AR, ER and IR on the same day!
After students have learned the subject pronouns in Spanish and understand the concept of subject-verb agreement, it is time to apply these concepts and learn the verb endings for regular –ar, -er and –ir verbs in the present indicative tense.
Most textbooks introduce –ar verbs, usually in the context of greetings, using llamar or hablar as models, then in subsequent chapters they take up –er and –ir verbs. I see no real pedagogical advantage in splitting them up into separate chapters to be taught on separate days. The concept is the same for all three families of verbs. As long as irregulars are not introduced, students will gain from getting a less myopic view of the verb system. Show them the forest, then examine each tree...
The best way to do this is by drawing the paradigm or grid for the subject pronouns at the top and center of the board, and write them in their respective boxes: singulars in the left-hand column, 1st, 2nd and 3rd persons in descending order and the plurals in the right-hand column, in the same descending order for the persons.
Immediately beneath that subject pronoun paradigm, draw another grid, labeled ER Verbs, but leave it empty for now. To its left, another grid labeled AR Verbs and to the right of the ER grid, the third and last grid, labeled IR Verbs.
Before proceeding, and while you have them in some suspense, ask them to define person and number to reinforce the concept and then tell them they are going to apply that knowledge so they can begin to use it. Knowledge that goes unused is like giving a bald man a comb.
So, next, tell them you are going to show them the anatomy of a verb.
Write hablar, comer and vivir above or next to each of the respective grids for –ar, -er and –ir verbs.
Tell them that these forms are known as infinitives because they have infinite possibilities. All they mean now is to speak, to eat and to live, but we don’t know who is doing these actions or when. In order to assign a "who" and "when" we conjugate a verb. In Spanish, this is done by modifying the ending now taken up by the AR, ER or IR. The "who" is the subject. The "when" is the tense -- the time of the action. For now, we are learning the present tense.
Ask them what a subject pronoun shows and lead them to define a grammatical subject as the “doer" of an action. Tell them that when a verb is assigned a subject and a tense, it is conjugated, that is, its ending is changed to correspond to that subject.
Next, have some method for labeling the three parts of a Spanish infinitive verb, then proceed as follows:
The final –r is the sign of the infinitive. The –a- , -e- or –i- is the theme vowel. It shows which family a verb belongs to. Tell them it is very important to remember which family a verb belongs to.
Finally, label the remaining parts of the verbs up to the theme vowel (habl-, com-, and viv-)and tell them that it is the stem of the verb, sometimes also called the root. It is the part that tells us what the action is. In this case, the actions of speaking, eating or living.
Finally, write the full conjugations of the verbs in their respective boxes. Ask a few students what a given form means. For instance, point to hablas and the student should say you speak. This is also a good point to ask about tú and usted or review as necessary.The follow up is to have a short list of regular verbs and call out short phrases in English and point to students, or give them a partially filled out grid and have them fill in the missing forms.