French agreement has nothing to do with opinions; it’s a grammatical function of the language. Just as verbs change to agree with their subjects in most languages (“I am” vs “you are”), so too do adjectives and pronouns in French: they change to agree in gender and number with whatever word they modify or replace (un homme fort vs une femme forte).
Most French adjectives have to agree with their nouns in gender and number, but there are many exceptions, known as invariable adjectives. These have just one unchanging form no matter the gender and number of the noun they modify. 
Magnetic poetry is a fun little tool you can use to learn and practice French. 500 magnets with words and parts of words help you to express yourself in a unique and creative way. agreement • plurals • verbs • word order
adjectives • agreement • nouns
Adjectives comprise one of the eight French parts of speech, but certain members of other grammatical categories can sometimes be used as adjectives. These "non-adjectives" are invariable: there's no gender/number agreement with the nouns they modify. adjectives • adverbs • agreement • B1 - Intermediate French • nouns • prefixes
Most French nouns and adjectives become feminine with the addition of -e, but there are some exceptions. Some nouns require an additional spelling change, depending on the final letter(s) of the word. adjectives • agreement • gender • nouns • spelling
Most French nouns and adjectives become plural with the addition of -s, but of course there are exceptions. A2 - Low-Intermediate French • adjectives • agreement • nouns • plurals • spelling
adjectives • agreement • nouns • word order
The indefinite French subject pronoun on literally means "one," but is usually translated by an indefinite subject. Agreement with the subject implied by on is optional - at least in theory. agreement • B1 - Intermediate French • indefinition • informalities • pronouns
French possessive adjectives (mon, ma, mes, ton, ta ...) are used in front of nouns to indicate to whom or to what those nouns belong. They are considerably more complicated than English possessive adjectives because French has several different forms depending on the gender and number of the possessed noun. A2 - Low-Intermediate French • adjectives • agreement • possession
French possessive pronouns (le mien, la tienne, les siens ...) are used in place of nouns to indicate to whom or to what those nouns belong. A2 - Low-Intermediate French • agreement • possession • pronouns
When used as a noun or adjective, the present participle follows the same agreement rules as other nouns and adjectives, and some verbs have a different present participle conjugation for these usages. A2 - Low-Intermediate French • adjectives • agreement • nouns • spelling
Reflexive pronouns reiterate the subject, which may seem redundant, but in fact serves an important purpose: it indicates that the subject of the verb is performing that action on itself. A1 - Beginning French • agreement • lesson plans • pronouns
In French, the past participles in compound tenses and moods sometimes have to agree with another part of the sentence, either the subject or the direct object.