Modo 14.0v2 docs:

Creating Geometry

Modo offers a variety of different tools for quickly generating geometry. Primitive items, such as spheres and cubes, are a good way to build basic forms, which can then be edited, added to, modified, and otherwise molded into the form you want, using any of the deform or mesh editing tools. Drawn curves are useful for creating wireframe skeletons of a form, where patches are then used to define the final surface. Functions, such as Solid Sketch, allow you to explore forms more readily without needing to manipulate specific geometry.

Primitives
	Cube	The Box primitive provides a simple method for creating boxes or cubes.
	Sphere	The Sphere primitive provides a simple method for creating sphere or balls.
	Cone	The Cone primitive provides a simple method for creating conical shapes.
	Cylinder	The Cylinder primitive provides a simple method for creating cylinders or tubes.
	Capsule	The Capsule primitive provides a simple method for creating capsules or rounded-edge tubes.
	Torus	The Torus primitive provides a simple method for creating toroids or "doughnuts".
	Ellipsoid	The Ellipsoid primitive provides a simple method for creating ellipses or "pills".
	Tube	The Tube primitive provides a simple method for creating spline curve-based tubes.
	Teapot	The Teapot primitive provides a simple method for creating a teapot.

Drawing
	Pen	The Pen tool allows you to create geometry vertex by vertex. You can use the Pen tool to create polygons, lines, vertices, spline patches, or subdivision surface polygons.
	Adding Curves	The Curve tool allows you to create a spline curve. This is a hermite curve type and can be very useful for creating modeling guides, quickly roughing out a shape, or setting up an outline for lofting with the extrude, lathe, or other multiply tools.
	Bezier	The Bezier tool allows you to create a type of curve defined by off-curve control handles.
	B-Spline	The B-Spline tool allows you to draw B-spline curves, which are spline curves defined by at least four vertices and a weight map.
	Sketch	The Sketch tool allows you to quickly create a curve by drawing in the 3D view.
	Arc	The Arc tool allows you to make closed segments of a disc (like the shape of a pie wedge, or a pie with a piece missing).

Curves
	Circle	The Circle tool allows you to create a circle using a Bezier or Hermite spline curve.
	Star	The Star tool allows you to create a star shape using a Bezier curve or a polyline.
	N-Sided	The N-Sided tool allows you to create a regular polygon with a give number of sides. it can be drawn using a Bezier curve or a polyline.
	Rectangle	The Rectangle tool allows you to create a rectangle or square, using a Bezier curve or a polyline.
	Ellipse	The Ellipse tool allows you to create an ellipse using a Bezier or Hermite spline curve.
	Diamond	The Diamond tool allows you to create a diamond shape using a Bezier curve or a polyline.

Other
	Solid Sketch	The Solid Sketch tool provides a quick method for roughing out organic shapes - building up basic geometry.
	Text	The Text tool simplifies the process of creating 3D text using system fonts.
	Vertex	The Vertex tool provides a method for quickly plotting points in 3D space.
	Make Polygon	The Make Polygon tool uses the currently-selected vertices to create a polygon.
	Patch Curves	The Patch Curves tool generates a smooth surface from three or four curves that define the contour edges of the surfaces.