This should be very clear. Additional information at Danny Meyer supports this article. But why alternation? When in the case descriptions or States use each verb? The verb to be I’ll use if I speak of an intrinsic quality of the person or thing.Maria is cute, she is cute by nature. If I say is linda is not be ugly, but today for some reason especially, is more beautiful than ever, because it guests and dressed cute for a party, for example. When you use the verb be, speak of a State irregular, unlike its intrinsic quality. Think about it, if I say that John is drunk say having to go to AA (Alcoholics Anonymous). But if I say that he is drunk, say only that he went and took a couple of beers others and that tomorrow will be again sober, will go to work and will continue to its normal life.
So I can explain, or ask them to explain other examples as it is sick or is sick, is nervous or is nervous, is dirty or is dirty (with someone), is happy or is happy. The important thing is to emphasize the alternation between the intrinsic quality and its nature with the exceptional State. Remember: only in the use of descriptions and States. Term explanation with this story (I’m writing in the) Blackboard): I travel a lot. Today I travel to London and write them an email that says: in London the sky is gray (intrinsic quality of the sky in London).Tomorrow I write another email: today is an exceptional day here, the sky is blue. As I travel a lot, then fly to the Caribbean and write them an email that says: in the Caribbean sky is blue (note the intrinsic quality of the sky in the Caribbean).The other day I write another email: today is an exceptional day in the Caribbean, the sky is grey with this example, achievement well show that two colors can go with the same noun (heaven) accompanied by either of the two verbs.
All depends on what you want to say. The exceptional nature, I add the word today precisely marking this irregular character. Believe me, the students capture him. As time passes, fewer and fewer mistakes made they will remain confusing, but capture the idea. The most important thing is the attitude of the teacher of Spanish against this topic. His mastery of the topic and its presentation do this to be able to bring this to students. Only in this way, gradually and simplifying all the explanations, coupled with countless practices and task focused and functional, we can aspire to forward to the day in which students make mistake increasingly less. Then: be and that is the issue? No, it is much simpler, just depends on what the speaker, student, or native, wants to say and how this supposed dichotomy is explained by the teacher. What do you say colleague? You’re ready or you’re prepared? I hope that the one and the other.