Spanish language Q&A Forum

I am interested in the reasoning for using "los cuales" in "no se sabe si permitirán a los niños a llevar sus móviles apagados dentro de sus mochilas, los cuales podrán encender al final del día".  My understanding is that "que" is used by default when referring to a specific noun, in this case "sus móviles", while "el/la/los/las cuales" is an optional, more formal alternative.  But in my answer the simple "que" was deemed incorrect.  Is this because the "que" would refer to "sus mochilas", being the noun immediately preceding, so the "los cuales" is required to disambiguate?  Or have I misunderstood something more basic?    

When I ask a question I would like to see if other people have asked a similar question, but when I try to search for my question, no search is done; I am only allowed to ask a new question.

Gracias, Jaime 

Some verbs in the preterite indefinido have tildes and some don't. Is there a rule for when they are used or not used, as i'm finding it difficult to remember when to use them?

It only says "We can also form the superlative of some adverbs with the suffix -ísimo", but not which ones these are. 

There's something on cerca & lejos, but how about other irregular adverbs (those having an independant form, like bien)?

It seems these would not have any -ísimo from, as I neither found "lo hiciste bienísimo" nor "lo hiciste buenísimo", but solely "lo hiciste muy bien".

Why lo de que? Maria is a noun. Why isn't it lo de?

I get that sentir goes before a noun and sentirse before an adjective. But in a test the question was "Yo siento que voy a explotar, comí demasiado."

How do we know whether to use sentir or sentirse in a sentence like this?

"Ellas han tenido que ser acompañadas...."

could this also be translated "Ellas tuvieron que ser acompañadas"?

thanks,

-alf-

Why is it “compramos dos billetes de ida y vuelta en ventanilla” and not LA ventanilla? I don’t think I’ve seen this before, it doesn’t seem to fit with the other rules on definite articles?

The correct answer for "Maybe I should sleep less" is given as: "Tal vez debería dormir menos tiempo", using the conditional. However, under "Your Practice" we are directed to: https:// + "progress.lawlessspanish.com/my-languages/spanish/view/5084" - which helps us to choose between: "Using El Subjuntivo or El Indicativo ... [after tal vez and quizás - to express doubt]".