Spanish language Q&A Forum

I wonder to know whether the second sentence need add ´´la´´ to indicate ´´the´´ meaning or not?  Thanks.

Nosotros todavía no salimos del trabajo.        /We haven't yet left work.

Juan todavía no salió de casa.      /Juan has not left the house yet.

When using de lo más with estar, specifically, is it preferred or more common to have the adjective agree with the subject, as distinct from when using ser for example? I noticed the specific example sentences using estar both have adjective agreement with the subjects. So I wasn't sure if this was supposed to be indicative or if it's just a quirk of having examples that were chosen at random, and I can't seem to find an answer anywhere else...

Why is creer not the right verb for "she thought that" . Difference between pensar and creer please? 

Hola. How do express the difference between "The students must not use a calculator" (in the examples), and "The students DON"T HAVE TO use a calculator." which has a very different meaning. Thank you! 

Are ´con tal de que´and ´a condición de que´ interchangeable ?

How do we get lessons to clear from our listing.  I seem to do the lesson, get both test questions correct, but the lesson stays in my list.'

Thanks.

.....antes fue a tontaría. I believe this should be 'lo de que' as 'ir is conjugated, but the answer shown as correct is 'lo de', why?