Spanish language Q&A Forum

I thought the past participle of leer is leído. But the above example uses leídas. I have no knowledge of conjugating past participles. Please explain the usage. Thanks 

Perhaps it would be helpful with these various stem changing verb lessons to explain more clearly that the vowel changes only affect the vowels when they are in syllables that are stressed, rather than giving the impression that the nosotros/as and vosotras/os forms are just arbitrary exceptions. I think that grasping that makes it a lot easier to internalize the pattern than just trying to memorize exceptions without understanding why they work that way. 

Isn't there an exception for locations of events? For example in: "¿Dónde es la reunión?"

¡Me gusta que nos muestre las dos formas de las frases, gracias! ;)

This word seems to change all the time! I had the wrong answer so next time it came up in a question I put the answer it gave me last time and it said wrong and gave the answer as the one I chose in the first place!  This has happened several times. How and why does this word change?

Are there lessons having to do with the pauses and intonation in Spanish speech? I guess I'm using English patterns to place commas and periods when transcribing spoken Spanish and am frequently wrong.