In French, a verb is inflected to reflect its mood and tense, as well as to agree with its subject in person and number. Following the tradition of Latin grammar, the set of inflected forms of a French verb is called the verb's conjugation. Stems and endings French verbs have a large number of simple (one-word) forms. These are composed of two distinct parts: the stem (or root, or radix), which indicates which verb it is, and the ending (inflection), which indicates the verb's tense (imperfect, present, future etc.) and mood and its subject's person (I, you, he/she etc.) and number, though many endings can correspond to multiple tense-mood-subject combinations. In certain parts of the second conjugation there is also a suffix -iss- between the stem and the ending, which derives historically from an inchoative suffix. In parlaient, the stem parl- indicates that the verb is parler (to speak) and the ending -aient marks the third-person plural imperfect indicative. "Third person plural" meaning the subject of the verb is "they". The "imperfect indicative" being a tense. In finissons, the stem fin- indicates that the verb is finir (to finish), the suffix -iss- follows it, and the inflection -ons marks the first-person plural present indicative or imperative. The "first-person plural" is the "we" form of a verb. The "present indicative" being a tense and "imperative" being a mood, but in French they are indistinguishable without context. These verb conjugations are most often coupled with a subject pronoun to reinforce who the subject of the verb is (i.e. who is doing the action). Note that it is sometimes difficult to distinguish the stem from the ending, especially in irregular verbs such as avoir (to have), aller (to go), dire (to say), être (to be), faire (to do, make), pouvoir (can), savoir (to know), valoir (to be worth, to cost), and vouloir (to want): Il va travailler. (He goes to work.) Es-tu là ? (Are you there?) Elle a rougi. (She blushed.) In these examples, there is no obvious stem - the verbs conjugate without a stem. The principle of the fixed stem The stem normally stays fixed in the first two conjugations: Parler: Je parlerais, tu parlas, qu'ils parlassent, que nous parlions, parlez… Finir: Je finirais, vous finîtes, qu'ils finissent, finis, que nous finissions… In the third it is often modified, sometimes even between persons in the same tense: Vouloir: Je veux,