Spanish language Q&A Forum

Why does one sentence use con terminación en., And the next sentence use  que acaban en for the same English construction? 

Some examples use the verb “estar”.  But can we ever use “ser”?  Ex:  “Mis primos fueron aburridos hasta que viajaron a españa.”  Thanks.

Why is "lo mío" singular? Why not "los míos son" or "lo mío es"?

The question did not specify to use the tú or usted form, and in a later question, it did specify "tú."  So I typed "leyó", but was marked wrong. I had "leiste" until I saw "tú" specified later, so I changed it.  Either both should be right or it should be specified, to reduce frustration.  I can see if you were talking to a family member or close friend (in an obvious context), then it should be expected to be "tú." But this was quite ambiguous- you could have loaned a book to a friend or a colleague or boss.

Are there other similar idiomatic expressions or must one use the conventional gramatical constructs? For example:

If you were me... (Tú que yo?) 

If I were him... (Yo que él?) 

If he were you... (Él que tu?) 

etc. 

In this exercise the preterit 3rd person singular of "creer" is shown as "crió" whereas in my other Spanish dictionaries it is shown as "creció". Is the former conjugation specific to Latin America whilst the latter (creció) is specific to Spain?