What are the two objectives in presenting a new structural item?

<p> When presenting a new structural item we should be primarily trying to achieve two things:<br> a) to enable the students to recognize the new structure well enough to be able to produce it themselves (ie. establish the form);<br> b) to make absolutely clear the usage of the pattern, so that when the students produce them, prompted by the teacher, they know what they are saying (ie. establish the meaning).</p>