Breakdown of Tu pourrais ajouter une pincée de cette épice ?
une
a / an (feminine)
tu
you (informal singular)
ce
this (before a noun)
de
of / from / any (in negative sentences) / about (concerning)
Questions & Answers about Tu pourrais ajouter une pincée de cette épice ?
How would I reply I added a pinch of it in the past tense? Does the past participle agree?
You would say J'en ai ajouté une pincée. Even though épice and pincée are feminine, the past participle ajouté does not agree (it does not take an extra -e) because the direct object is the pronoun en. As a general rule, past participles remain invariable when the direct object is en.
Is épice feminine? I thought nouns starting with a vowel took cet instead of cette.
Épice is indeed feminine, so it takes the feminine demonstrative adjective cette. The masculine form ce changes to cet before a vowel (like cet arbre) to make pronunciation easier. However, the feminine form cette remains exactly the same whether the next word starts with a consonant or a vowel.
How would the meaning change if I said une pincée d'épice instead of une pincée de cette épice?
Saying une pincée d'épice simply means a pinch of spice in general. This is because after an expression of quantity like une pincée, you use de without a definite article. By adding the demonstrative adjective cette, the speaker is being specific and pointing to this particular spice.
Why use the conditional instead of the present tense ?