Examples in Spanish:
You don't say: "leer entre las líneas" ................... you say "leer entre líneas".
Natural English:
the fast train
fast food
a quick shower
a quick meal
have a good time
spend some time
rich vocabulary
take a break
take an exam
Unnatural or Wrong English: DON'T SAY:
the quick train
quick food
a fast shower
a fast meal
pass a good time
pass some time
wealthy vocabulary
do a break
make an exam (the teacher makes or creates it, the student takes it)