Why? " Stayed" is given as an alternative for estuviste. Does it just mean " you were" and in which case why should "stayed " be given as an alternative?
I'd like to know this as well, since it says that "estuve" could mean "stayed."
Estuviste is the preterit of estar, but it certainly doesn't show up much in DL so far. They use the same verbs over and over again.
Not usually. Being "at" a boat is like being in the same location as the boat, but not in or on it. If you are standing next to a boat, then yes, you are at the boat. However, if you are walking on the deck of the boat, you are either in or on it.
I thought ... When were you at that boat .... How can you tell if en means on or at?
'Estuviste' is the 'tú' form conjugation of 'estar' in the preterite. There is nothing ambiguous about it.
Just like any other verb and tense, estar has different forms for each person and number in the preterite tense. They are as follows:
Yo estuve / Nosotros estuvimos
Tú estuviste / Vosotros estuvisteis
Él estuvo / Ellos estuvieron