Starting with your form intersections, while these are progressing decently, there are still mistakes that seem to me to come about less from a lack of understanding of how these forms relate to one another, but perhaps confusion that arises from trying to understand which way your forms are oriented. I've marked out some corrections here - look closely at the ones I marked as A and B in your original page - for A to be close to correct, that end should be oriented towards the viewer. For B to be correct however, that lower end would have to be facing the viewer instead. In my corrections, I treated A to be the side pointing towards the viewer, leaving the cylinder to intersect with the side plane for B, rather than the other end. This is also not aided by the fact that the cylinder itself appears to get bigger as it moves farther away from the viewer (I treated the end closer to the box to be facing the viewer, since that appeared to line up better with your intersections, and it had the narrower degree - but the other end is definitely larger in overall scale).

Moving onto your cylinders in boxes, your work here appears to apply the procedures correctly, so all seems to generally be in order here.

While the form intersections were admittedly a rough start, your work throughout the rest of the lesson is definitely better, and does not show the same kind of confusion. That said, there are some important points I want to draw to your attention, that should help you make more out of these exercises.

First off, in terms of the "form intersection vehicles", it appears that you may have taken this exercise much farther than intended. The intent here was not for you to worry about subdivision and applying the outer grid, but to simply build up primitive forms in the arrangement of a vehicle - as though you were doing the form intersections exercise, but arranging them in a particular fashion rather than randomly. The goal is to help reinforce the idea that we're still working from simple to complex, building up basic forms and carving them down to achieve more complexity, and that this is the manner in which we need to be thinking as we move into the later constructions where the outside-in approach of laying down that grid and subdividing plays a bigger role.

Fortunately I think you held to this core focus despite taking those drawings further than intended - you're still working with primitive forms, arranging them according to their set dimensions and scale, at least when doing this part of the exercise.

Continuing onto your vehicle constructions, one point I did want to call out is that as noted here in the instructions you should not be changing pens through the process. From what I can see, there is definitely a notable difference in the linework you employed for your initial grid and in the later linework for your later constructions (from the airplane onwards). The manner in which you approached the earlier ones, where you used line weight more subtly and refrained from outright redrawing the entirety of the object, was more in line with what I was expecting, given the instructions.

This also appears to go more in hand with a change in how you approached drawing the vehicles themselves - with a greater distinction between the grid/subdivisions/scaffolding and the final result itself, as though you were trying to create a cleaner, more separated drawing rather than focusing on the exercise at hand. Everything in this course is after all, an exercise, with the goal never being to create a pretty picture at the end.

In this regard, you also stray more and more from the idea of working with primitive forms and building up from simple to complex, to jumping from the grid to your drawing. While that's not strictly incorrect on its own, it's a matter of how you're thinking, whether you're constructing the object on the flat page, or in a 3D world. You do an excellent job of laying down the initial structure in three dimensions (that is, the subdivision of the grid and whatever other primitive elements you do include - like the wheels in this one, where we can see how you've constructed them initially on the opposite side of the structure.

Remember - tracing, as a concept, is an act that has us focusing more on how the lines we're following run across the page in two dimensions. So, if you're laying down that basic structure/grid, and then trace back over elements of it to draw a complete, otherwise cleanly separated drawing of a car, then it's going to come out feeling more flat. Instead, if you hold to the principles we've used throughout this course, you'll still be thinking about building up boxes, then cutting into forms, or adding yet more forms - thinking in the manner of carving with a knife, rather than drawing on a flat page.

With that said, I'm going to assign you two more pages of vehicle constructions. I can see clearly that you have every capacity to push the constructional side of things, but I do want to see you take a construction as far as you reasonably can without changing modes as you've done here. In all fairness, this is very well done, in regards to everything I've addressed, so if you hit that for the additional two, you'll be good.

Oh, one last thing - remember that filled areas of solid black should be reserved for cast shadows, and when you fill in the surface of a given form as you did here on the side of this wheel you are engaging in form shading instead, which is not to be included in our drawings for this course (as explained here.