Its suppose to be
C'est cette porte, la. (with accent)= C'est la porte, la. (with accent)
It just said that this needs special attention and I don't know why.
Matinal! (early bird)
This is the demonstrative adjective/pronoun for this (one), that (one), these (ones).
The only way to tell if you want it to be "THIS" vs. "THAT" is by adding -ci (this) or -là (that).
The demonstrative adjectives are: ce, cet, cette (this, that) and ces (these, those).
ce + masculine singular noun beginning with a consonant = ce moulin (this/that mill)
cet + masculine singular noun beginning with a vowel or silent h = cet appareil (this/that instrument) or cet hiver (this/that winter)
cette + feminine singular noun = cette revue (this/that magazine)
ces + all plural nouns = ces moulins (these/those mills) or ces revues (these/those magazines)
NOTE: The demonstrative adjective must be repeated before each noun.
ce lac et cette plage (that lake and beach)
ces aiguilles et ces épingles (these needles and pins)
If it is necessary to distinguish between "this" and "that" or between "these" and "those" -ci and là with hyphens are added to the nouns contrasted. To mean "this" or "those" add -ci; to mean "that" or "those" -là is added.
cette écriture-ci ou cette écriture-là (this handwriting or that handwriting)
ces poèmes-là et ces poèmes ci (those poems and these poems)
My students used to say "it's like saying this here and that there." Although I prefer not to say that, fine, if it helps you!
________________________________________
Although you aren't to the demonstrative pronouns yet, have a look. If you're not ready, just save it for later.
The forms of the demonstrative prnoun "celui" are: celui, celle, ceux, celles
Celui and its forms are not used alone. They are generally used with one of the following: de, -ci, là, qui, que, dont
celui de, celle de = the one of
ceux de, celles de = the ones (those) of
Donnez-moi mon billet et celui de Gautier. (Give me my ticket and Walter's.)
Il portait ses propres livres et ceux de sa soeur. (He was carrying his own books and his sister's OR those of his sister.)
celui-ci, celle-ci = this (one), the latter
celui-là, celle-là = that (one), the former
ceux-ci, celles-ci = these, the latter
ceux-là, celles-là = those, the former
Quelles fleurs préfèrez-vous, celles-ci ou celles-là? (Which flowers do you prefer, these or those?)
Lamartine et Balzac étaient écrivains; celui-ci était romancier et celui-là poète. (Lamartine and Balzac were writers; the latter was a novelist and the former a poet.) NOTE: The "celui-ci" is the latter because it's closest to the END of the sentence and "celui-là" is the former because it is farther away from the end.
celui qui, celle qui (the one that, as subject)
celui que, celle que (the one that, as object)
ceux qui, celles qui (the ones/those that)
ceux que, celles que (the ones/those that)
ceux dont, celles don't (the ones of which)
Ceux qui travaillent dur réussissent. (Those who work hard succceed.)
La maison blanche est celle qu'ils vont acheter. (The white house is the one they are going to buy.)
C'est celui don't je vous ai parlé. (This is the one I spoke to you about.)
Now, aren't you glad you asked?!!
Mme