Spanish language Q&A Forum

In the above examples, all of the feminine objects (gafas, pruebas, ausencias) are plural so that the past participle of the action ends with -as. Does this mean that for a single object (chica, casa, etc) the past participle takes on -a?

Example: La casa fue construida por Miguel. 

Hello, 

In the test for this lesson, when it asked for a formal answer to ask Gerardo how he's doing, I selected "Comó está" and it said the response was nearly correct, and that "qué tal" is the correct response. 

Why is "qué tal" considered more correct in this scenario than "comó está"?

Rather than giving a dozen examples (which frankly seem as though could be interchangeable) I wish this section would begin with usage rules... under what general circumstances does one typically apply cada vs toda? And then under each rule place the examples to illustrate and underscore.

I didn't go by train but by car.

habra convocatorias

I feel like there are 2 correct answers to this question:

Es el hombre más honesto ________.

He's the most honest man I've ever met.

I think the one I choose and the one identified as correct are equally correct. 

que jamás haya conocido - identified answer 

jamás yo he conocido - my answer 

Please explain.  Thank you