You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Catalan_language

Context:
As in the other Western Romance languages, the main plural expression is the suffix -s, which may create morphological alternations similar to the ones found in gender inflection, albeit more rarely. The most important one is the addition of -o- before certain consonant groups, a phonetic phenomenon that does not affect feminine forms: el pols/els polsos ("the pulse"/"the pulses") vs. la pols/les pols ("the dust"/"the dusts").

Question:
What is the usual way to make a plural?

suffix -s