Fuiste, eras. Leal.
This one has me by the short hairs.
Le diré que fuiste leal hasta el final.
Now it seems like you are loyal all the time. not a point in time. Eras.
Then I thought.
Desde -----------> Hasta.
Then I thought.
Le diré que fuiste leal (desde el principio) hasta el final. Bam, Start and End. So maybe "hasta" by it's very nature implies desde.
Then I asked at work.
And they said "leal" tends to go with fuiste. But I don't get it. Mi perro era leal. Le diré que fuiste leal.
Le diré que fuiste leal.
Le diré que estabas leal.
Le diré que eras leal.
Then I thought.
If it was eras then he would already know you were loyal, you are a loyal person. If it was fuiste then are being loyal, similar to estar but not a temporary action.
Then I wrote this message.
3 Answers
Yo can use both, "fuiste o "eras", but the meaning it's not the same.
"Eras leal". You were loyal at that time but you are not anymore.
"Fuiste leal". You were loyal. No second meanings about the actual state. This will mostly be used to talk about an specific situation.
To say that somebody is loyal, with no timeline, you use the present: "eres leal".
"Estabas leal" is incorrect. You can't say "tu estás leal" because "ser leal" means being loyal.
"Fuiste" is the past of "ser". "Fuiste leal" -> You were loyal.
I've heard the same. One of those oddities that probably makes perfect sense to a native, but not much to learners.