Final answer:
The endings for third declension M/F adjectives in Latin are 'is' for masculine singular, 'is' for feminine singular, 'e' for neuter singular, 'es' for masculine and feminine plural, and 'ia' for neuter plural.
Step-by-step explanation:
The endings of third declension masculine/feminine (M/F) adjectives in Latin are generally is, e, and es. These endings are applied to the stem of the adjective to agree with the gender, number, and case of the noun they are qualifying. For instance, in the nominative case for singular forms: the masculine usually ends in -is, the feminine in -is, and the neuter in -e; for plural forms: the masculine and feminine typically end in -es, and the neuter again in -ia.
An example of the use of these endings can be seen in the adjective 'fortis' (brave), which is the same in both masculine and feminine singular forms, and 'forte' in the neuter. The plural forms would be 'fortes' for masculine and feminine, and 'fortia' for neuter. It's important to note that these are general guidelines and some adjectives may have irregular forms or exceptions.