Chapter Two: The Basic Sentence
Lucien Tesnière, “Sketch of Structural Syntax”
Verb
The verb is the node of nodes. It is, directly or indirectly, the governor of the entire sentence. As such, it is placed at the top of the stemma. That is why it is best practice to start with the verb when drawing up a stemma: Votre charmant nièce donne à mon malheureux cousin un livre magnifique.

The immediate subordinates of the verb are the actants and the circumstants.
Actants
We call actants, the subordinates of the verb that in some way participate in the action. There are three kinds of actant: 1) first (or prime) actant or subject, 2) second actant or direct object and 3) third actant or indirect object.
Sometimes it is useful to number the actants on the stemma.

This preceding line of thinking leads us to the unexpected conclusion that the subject is a complement like the others.
Translation from one language to another is sometimes impossible without switching the actants:

Circumstants
We call circumstants the subordinates of the verb that indicate the circumstances of action: time, place, manner, etc. The number of circumstances is unlimited: Alfred passera rapidement là-bas demain.

In the stemma, we will always place the circumstants to the right of the actants.
Epithet
An epithet is the subordinate of the substantive: Le signal vert indique la voie ouverte.

The number of epithets is unlimited: Votre joli petit chat blanc.

The epithet can for its part have a circumstant as a subordinate, which can itself have a circumstant as a subordinate: Mes hommages très profondément respectueux.

Apposition
Apposition is a horizontal connection: Orateur remarquable, Atticus écrivait médiocrement.

Apostrophe
Apostrophe acts as a first actant of the verb in the imperative: Prends un siège, Cinna.

