Learn Spanish (Latin America): Protestemos por la justicia, pero seamos pacíficos. - Let's protest for justice, but let's be peaceful.

To say "let's [do something]" in Spanish, we use the nosotros (we) form of the present subjunctive. For -ar verbs like protestar, the vowel swaps to an "e", giving us the ending -emos. That is why it translates to "let's protest."

Where does the word seamos come from?

It is the "let's" command form of the verb ser (to be). Because ser is highly irregular, its present subjunctive form becomes seamos ("let's be").

Why do we use por instead of para in por la justicia?

We use por because it expresses the cause or motivation for the protest. You are protesting on behalf of or for the sake of justice. Para is generally reserved for goals, recipients, or physical destinations.

Why do we use a form of ser (seamos) instead of estar for "let's be peaceful"?

We use ser because being peaceful (pacífico) is considered an inherent characteristic or a core personality trait of the people protesting, rather than just a temporary physical state or condition.