Estas loco - You are crazy (now) - Something you say when some one is doing something looney or rude or inappropriately funny.
Eres loco - You are a crazy person - Something you would say if some one is doing something that could be life-threatening or dangerous or damaging.
As to pronunciation, Spanish is a phonetic language.
a always sounds like the a in "at"
e always sounds like the e in "Bet"
i always sounds like the i in "Machine"
o always sounds something like the second o in Robot. Our like the ou in bought
---notice there is no "oo" sound after the o sound in the Spanish letter o EVER. It's not lo-oo-co-oo.
u sounds like the oo in "boot" EXCEPT when preceded by a C or a G AND followed by an E or I. Then it is silent UNLESS it has two dots over it like ü.
The consonants sound close enough to the English counterparts. The C in this case sounds like a K
because when u try to answer a question n it and u answer it wrong they say u crazy
im not crazy in 100 different languages
loco
Bésame el trasero that's how u say you are crazy about me
You can say "Estoy loco(a)".
¿Eres loco?
Estamos locos
No estoy loco
Me vuelves loco/a.
You say, "tortuga loca."
im aplastamiento
You could say "Sombrero loco".