Spanish language Q&A Forum

Why whenever I use sobre in a sentence its followed only by 'la/el'? These examples are taken from the course I'm doing on Duolingo. 

E.g. El gato esta sobre la mesa. 

But if I use debajo its followed by 'de la/el'. 

Mi celular esta debajo de la ropa. 

Is there a reason for this? 

Why does one use just 'la/el' but the other needs the 'de' to be marked correct? 

One question was ____________  mucha niebla. Hay or esta.  I used esta wrong.  In fact mucha is never even translated.   So why is it Hay, not esta and why isn’t mucha translated 

I got this sentence in a quiz

No puedo ver _____ en la muchedumbre.  

The answer was "a Paula y Cristina".    

I notice that sometimes you put an a before every name, like "a Paula y a Cristina". Is this optional, or are there certain circumstances when the a is required before each person?   

Quiz statement:  Esa profesora explicaba muy bien pero esta nos aprobaba fácilmente.

My translation: That teacher explained things very well but this one passed us easily.

Quiz translation: That teacher explained things very well but with this one we passed [the subject] easily.

How I would translate that back into Spanish: Esa profesora explicaba muy bien pero, con esta, aprobamos fácilmente.

The translation of the second clause seems to change the focus, with the subject being the teacher (passing the students easily). I realize it’s subtle but do you think it makes a difference? Did the second teacher go easy on the students or did they just connect better with her teaching?

When I took the ¿Cómo Estás? A2 Kwiz related to this subject, this question below was marked wrong ("feliz" in red), saying my answer should have been "contenta". Since they both refer to being Happy, can you explain why Contenta is better in this sentence?

MARÍA: Venga chicas, ¡ánimo! Yo estoy muy feliz, ¡tengo un trabajo nuevo!

With "tener que + infinitive" do you have to attach the pronoun to the infinitive or can it also be placed before "tener"?

Example: Tengo que lavarme las manos.

Me tengo que lavar las manos.

Are both sentences correct or is only the first sentence correct?

Buenas tardes, 

Whenever I click on the link for the lesson on conjugating ‘Hacer’ en el Futuro Simple I am brought here for conjugating ‘Salir’ en el Futuro Simple.

I’d be most grateful if you could check this out of me.

Can I use it without and with que interchangeably?