"Te quiero" in Spanish should not translate as "I love you". "Te
amo"
is the actual phrase.
Te quiero has a simiar meaning, but is just not as strong. Similar to
"dai suki" (not taken in literal sense, as that would be [en]"I like
you" = [es]"me gustas") vs. "aishiteru" in Japanese, I guess. I
don't
think there's any real equivalent in English.