ABOUT RULES:

What makes a rule a good rule? Michael Swan (1995 cited by Thornbury 2005:32) offers the following criteria:
1) Truth. They must bear some resemblance to the reality.
Definitely, the actions of the present continuous tense have a great resemblance to the reality specially if in the classroom one Ss is talking with other peer and another partner comes and ask “What are you doing”. And in the case they are at home and a friend of them arrives.
2) Limitation. Show clearly what limits are on the use of the given form.
About this, the limitation was well established because I told them the present continuous tense is used to describe actions taking place now, in the present.
3) Clarity. Clear terminology
I tried to use terminology they already know in order to not confuse them with a new word. However, I strongly believed more vocabulary was necessary. I say this because as Thornbury (2005:15) points out “the number of possible new sentences is constrained only by the vocabulary at the learner’s command” and in this case, the sentences were really limited. So, I need to provide them with more expressions and vocabulary.
4) Simplicity. Simple without overburdening the rule with sub-categories
I intended to use only one form and only one function and, of course, I gave the meaning to them. (The Tridimensional Grammar)
5) Familiarity. Use of concepts already familiar to the learners
Using terminology that my Ss already knew was the key since it was easier for them to understand the phrases and vocabulary used.
6) Relevance. Answer only those questions that the Ss needs answered.
I try to answer their questions using mimic, words, phrases, etc.
SOURCES:
Michael Swan (1995 cited by Thornbury 2005:32) “Practical English Usage” (New Edition) Oxford University Press
Thornbury, S., (2005) “How to Teach Grammar” Longman