Does anyone know when you should add e's/s's to french verbs, and when you shouldn't? I understand the purpose, to make feminine or plural depending on what gender the subject is. But what types of verbs should you add the e's/s's to? Would you add them for...

choisi
fait
vu
envoye(pretend that e is an accent aigu)

~Merci for your help

If I understand your question, because you have past participles above: choisi, fait, vu, envoyé.....you are referring to the agreement of past participles conjugated with avoir, or the passé composé, with preceding direct objects. Then the past participle agrees in number (singular/plural) and gender (masculine/feminine) with that preceding direct object.

Some examples:
That is the house that I have chosen = C'est la maison que j'ai choisie. (Note the past participle being singular and feminine just as "la maison" is, because "la maison" is the preceding direct object.

Here is the homework (the tasks) that he has done. = Voici les devoirs qu'il a faits. (masculine & plural)

Ce sont les jeunes filles que nous avons vues. These are the girls that we have seen. (feminine & plural)

Ce n'est pas le livre qu'ils ont envoyé. = That is not the book that they sent. (It may appear there is no agreement because "le livre" is masculine and singular.)

Please feel free to ask any questions. Was this what you were referring to in your post.

Since one can not "pretend" to imagine accents where they should be, if you tell me 2 things, I can provide the chart for you to make accent marks on the computer.
1. Do you have a MAC or PC.
2. Do you have Windows or not.

Sra (aka Mme)

P.S. Although you did not ask, past participles conjugated with être, agree in number and gender with the subject. (1)

Examples:
Quand sont-ils sortis? = (When did they leave?)

Sa femme est née en Afrique. = (His wife was born in Africa.)

It is a bit trickier with Reflexive Verbs in that the reflexive pronoun *me, te, se, nous, vous, se) is not always a direct object. It ma be an indirect object, with or without a direct object expressed in the sentence. (2)

Examples:
Ils se sont arrêtés court. = They stopped short.

Où sont les cravates qu'il s'est achetées? = Where are the ties he bought (for himself)?
Elle s'est brossée. = She brushed herself.

BUT: Elle s'est brossé les cheveux. = She brushwed her hair. (her hair is a following direct-object and the "s'" in this case is the indirect-object pronoun)

Nous nous serions écrit. = We would have written to each other (ourselves). (The direct-object "probably letters" is not stated and the reflexive pronoun is again an indirect-object pronoun.)

With the verb "parler" has no agreement because it takes an indirect object. (3) Nous nous sommes parlé. = We spoke (words, etc.) to each other.

Past participles can also be used as adjectives and must agree with the noun they modify. Les bijoux étaient cachés. = The jewels were hidden.

Je dis que le latin n'est pas une langue morte. = I say Latin is not a dead language.

Sra (aka Mme)

In French, adding e's or s's to verbs is a way to match the verb with the gender and number of the subject. This is called verb agreement. Let's break it down to understand when to add e's or s's to verbs.

1. Feminine singular subject:
If the subject is singular and feminine, you add an e at the end of the verb.
Example: J'ai choisi (I have chosen) becomes J'ai choisie.

2. Plural subject:
If the subject is plural, regardless of gender, you add an s at the end of the verb.
Example: Ils ont fait (They have done) becomes Elles ont faites.

3. Feminine plural subject:
If the subject is plural and feminine, you add both e and s at the end of the verb.
Example: Elles ont vu (They have seen) remains the same because the verb vu does not change.

4. Verbs ending in -yer:
Verbs ending in -yer (e.g., envoyer) have a spelling change in the present tense for the first and second-person plural forms.
Example: Nous envoyons (We send) becomes Nous envoyons.

Remember that these rules apply to the present tense of regular verbs. Irregular verbs might have unique conjugation patterns.

To check verb agreement, you need to know the gender and number of the subject. Choose the appropriate form of the verb based on these factors.

I hope this explanation helps you understand when to add e's or s's to French verbs!