Breakdown of L'érosion est rapide parce que la roche est poreuse.
être
to be
rapide
fast
parce que
because
la roche
the rock (material)
Questions & Answers about L'érosion est rapide parce que la roche est poreuse.
The current lesson is about using c'est for generalizations. Why doesn't this sentence use c'est rapide or c'est poreux?
Using c'est followed by a masculine singular adjective is great for broad, general statements in everyday speech. This sentence, however, uses the standard est along with adjectives that agree with their feminine nouns. This tells us we are likely reading a more formal, scientific statement, or talking about a specific rock and a specific instance of erosion rather than making a sweeping, informal generalization.
Why does the adjective poreux change to poreuse here?
In standard French grammar, the adjective must agree with the noun it modifies. Since la roche is feminine, the masculine ending -eux changes to the feminine -euse. If we had used the informal generalization structure from this lesson, it would have stayed masculine singular: La roche, c'est poreux.
Could I use à cause de instead of parce que to say 'because' in this sentence?
You cannot use à cause de here because it must be followed directly by a noun or a pronoun, not a full conjugated verb. Since la roche est poreuse is a complete clause with a subject and a verb, you must use parce que. To use à cause de, you would have to change the grammar entirely, such as saying à cause de la porosité de la roche (because of the rock's porosity).
Is there a trick to remembering that is a feminine noun?