Agreement with adjectives that end with 's'

Agreement with adjectives that end with 's'

Can someone tell me how to use cortés properly with a feminine singular word like 'señora'? I doubt very much that cortés is the only adjective of that kind. Can someone suggest a couple more adjectives that behave that way? I know that mayor, peor and mejor will behave in a similar fashion, but I am interested in adjectives that end in "s" like cortés". The word 'francés' comes to mind but I do not believe it behaves like cortés with a word like señora. Thank you very much once more for your assistance.

The adjective "cortés" is invariable for gender. The plural is "corteses".

un señor cortés
una señora cortés
unos señores corteses
unas señoras corteses

Spanish has 3 types of adjectives:
1. Many adjectives have two singular forms (one masculine and one feminine) and two plural forms (one masculine and one feminine), for a total of 4 forms. For example, bueno/buena/buenos/buenas = "good".
2. Many adjectives have one singular form (both masculine and feminine) and one plural form (both masculine and feminine) for a total of 2 forms. For example, pobre/pobres = "poor".
3. A small number of adjectives have only one form that is used for all genders and numbers. For example, some color names have only one form, such as marrón = "brown".

A good dictionary should indicate the pattern for each adjective in its entry.

Adjectives whose masculine singular forms end in a consonant are often challenging to learn, as there is no absolute rule about whether there is a separate feminine form or not. Some final syllables (és, ón, ol) often have distinct feminine forms (esa, ona, ola), especially adjectives of nationality or ethinicity, but there are exceptions to most of these groups; in the end you have to learn the pattern for many adjectives individually.

I am indeed grateful for your response, but I still need some more information to resolve the issue I have raised. Remember my concern is primarily with adjectives that end in "s". I am not aware of other adjectives that end in "s" and behave like "cortés". I would really like to know a few more adjectives that behave like 'cortés'. The words 'inglés, francés, and portugués' do not behave like 'cortés' when they describe a feminine singular word like 'familia'. More adjectives like 'cortés', anyone?

The nature and origin of those words is very different: "Inglés", "francés", etc., can be both nouns and adjectives; "cortés" is only an adjective.

In addition to cortés, I only found these two that act the same way:
montés
gris

Here's a list of adjectives ending in z that don't have a feminine form.
atroz
capaz
feliz
feroz
fugaz
locuaz
sagaz
soez
tenaz
veloz
veraz

There are many other adjectives, ending in other consonants and vowels, that don't have a feminine form. Why the interest in just those that end in -és?

Million thanks to everyone, and a million and one thanks to Rusty. My gut told me that 'cortés' could not be the only adjective ending in 'és' that behaved that way. Naturally, I was more than overjoyed to be introduced to 'montés' and to the expression 'cabra montés'. To me, it is easier for the second language learner to err with montés than with salvaje. Interestingly, even the forum's dictionary gives montés -esa adj.' but with the example 'cabra montés'. The question that arises now is whether using montesa with cabra is an option. Oh, the challenges and joys of learning a second language.

It isn't. The RAE gives you another examples as well:

montés.
1. adj. Que anda, está o se cría en el monte.
□ V.
cabra montés
cochino montés
gato montés
puerca montés
puerco montés
rosa montés

http://buscon.rae.es/draeI/

If you want something to learn by heart, most of the adjectives that don't change with gender (only with plural) end with -i (cursi), -í (baladí), -ú (hindú), -z (veloz), -r (particular), -l (elemental)...
Also many ended with -a (agrícola, maya) and most of those ended with -e (verde, confortable).

Thank you very kindly, Angelica and all the members of the forum. I did not desire to learn anything by heart nor was I troubled by adjectives ending in z, í,ú and such like. I was concerned with 'cortés' and any other adjective/ adjectives that behaved liked 'cortés' as I tried to explain perhaps unsuccessfully before. The forum has been excellent for, in addition to dealing with my problem, considerable light has been shed on the behavior of adjectives that are invariable or irregular in some way. Viva tomísimo.

Can someone shed a little light on "montesa"? How can it be used? I am thinking of montés montesa as per dictionary.

"Montesa" is not heard frequently, but it's simple: "una cabra montesa" = "una cabra montés"