9.10.3 Reduced relative clauses
When the relative word is the subject, we can often reduce a relative clause by not including the relative word and the auxiliary verb be. This is possible with active clauses, e.g.:
 | Most of the people (who were) waiting were holding flags.
(La mayoría de las personas que esperaban llevaban banderas.) |
 | The new law will help workers (who are) earning less than €10,000 a year.
(La nueva ley ayudará a los trabajadores que ganen menos de 10.000 € al año.) |
 | I didn't notice the animals (that were) sheltering under the trees.
(No me di cuenta de que los animales se cobijaban bajo los árboles.) |
It is also possible with passive clauses, e.g.:
 | The article mentioned the soldiers (who were) killed in the war.
(El artículo mencionó a los soldados muertos durante la guerra.) |
 | I prefer vegetables (that are) well seasoned.
(Prefiero las verduras bien condimentadas.) |
 | The teacher doesn't accept essays (that are) written in red ink.
(La profesora no acepta los ensayos escritos en tinta roja.) |
 |