Let’s use the first sentence as an example of how to use these in class. Do not write the sentence on the board at this point. First, focus the class by announcing the pronunciation exercise (e.g., Atención, clase: ejercicio de pronunciación, escuchen con cuidado…). Now say the sentence, just a bit more slowly than natural speed.
Pause and repeat it. Next, tell them to repeat it together (ahora, repitan Uds.). Then have each student repeat the sentence at least once. Model correct pronunciation when you hear, for instance, the h of historia or a glottal stop between La and historia or a glottal stop before the i of interesante (the s of es should elide with it), or after the final –e of interesante. The word difícil is almost always stressed incorrectly by English speakers, even if they have never taken French!
The final i in difícil is almost always mispronounced as the i in the English words ink or milk. Don’t make anyone repeat the sentence more than three times. If they still don’t get it, make mental notes of the types of errors committed. By the time you’ve gone through the whole class, you’ll probably have a comment on each syllable!
After the whole class has had a chance to practice the sentence, you have two options: either use it as a dictation – to see how well they have listened and to check any spelling lessons they may have had previously, or you can write the sentence on the board and begin commenting on syllabification, the silent h, glottal stops (a no-no in Spanish), etc.
On each of the following four classes, start the class with the mantra exercise (i-e-a-o-u), then follow with the next sentence. After the second day, ask if anyone notices which vowel is being emphasized and ask them to guess what vowel the next class will be devoted to.
This simple question encourages meta-cognitive processes, a fancy way of saying taking responsibility for your learning by being actively engaged in it!