American Tango Primitives
The primitives are building blocks of simple figures. Even tango basic is a combination of two primitives. Thus, primitives are useful to consider on their own but usually the figures comprise of more than one primitive, and primitives do not by themselves form complete figures.
This is simply a forward walking step, sometimes called simply "walk". Most frequently the progressive walks occur in pairs and start from the left foot, thus the next figure also starts with the left foot. Progressive walks are done in closed position.
Leader's steps from closed:
LF forward (1-S) RF forward (3-S)
Back walks (for the leader) in tango do not seem to be a thing. In other words, walks are always forward.
Progressive walks (usually two of them) can be added or removed from the front of a figure to make it fit into a multiple of 4 or 8 counts. Two consecutive walks is usually the maximum done.
Leader's LF steps left of follower, RF forward steps between follower's feet, just right of follower's right thigh.
The walks can curve left about 1/8 turn between the two of them to set up the correct direction for the next figure.
This is just like the progressive walk but the leader takes the RF forward step outside partner.
This is a walk done in promenade position.
This is a walk done in shadow position.
Leader's steps from closed:
LF forward (1-Q) RF right (2-Q) LF tap together (3-S)
The (3-S) step is a tap - without weight change, as the next step normally would begin with LF again.
Some instructors specify that the final step of tango close should be a drag (walk-side-drag), others prefer to close the foot without dragging it or close partially and then move LF forward into the next step.
Tango close lends itself to curving left (for example, to go from DW to LOD) to set up the direction of the next figure appropriately.
Back Tango Close
From closed, leader's steps:
LF back (1-Q) RF right (2-Q) LF tap together (3-S)
Back tango close lends itself to curving right (for example, to go from LOD to DW).
Rocks replace walks in tango figures. Pairs of rocks can also be added in the middle of a figure as they do not change partners' relative position or which foot each is on.
The basic rock step is:
LF forward (1-Q) rock RF (2-Q) LF forward (3-S)
They can also be done from RF, of course.
As with walks, rocks are generally moving forward for the leader and back for the follower.
In the rocks, the (3-S) step should progress forward compared to the (1-Q) step, as opposed to being in the same place. This means the first rock step should be somewhat shorter than normal forward walk, with the third step being of a normal stride. It is better to shorten the first step rather than lengthening the third step because the follower wouldn't be able to extend further on the third step if the first step ended up using her full stride.