Honestly, despite your struggles and the challenges you've faced, you've done a pretty solid job here. You've largely demonstrated a strong grasp of 3D space and construction as a whole, and while there are a number of things I will point out to help you continue to grow and improve, you've definitely got a lot to be proud of here.

Jumping into your form intersections, I definitely agree that these are still very difficult for you. They are admittedly some of the most difficult spatial problems you'll face - more difficult than anything we encounter in actual drawings of real objects, but all the same, it is definitely an area you'll need more practice in, and that would perhaps require more time spent thinking before putting your marks down. I marked out some corrections here. In addition to thinking more about how intersection lines are essentially lines that exist on the surface of both objects simultaneously (meaning that if you pick any one point along an intersection you've drawn, you should be able to ask yourself whether or not it sits on both, and if it happens to be inside the volume of one of the forms, or way off in space relative to one of them, then it is incorrect), I want you to put more focus into drawing the forms such that they feel solid and cohesive. For example, if we look at the top-right cone in the page I marked up, you'll notice that the form feels somewhat weak relative to its neighbours. There's no line weight to really make it feel solid. Instead, you've largely used line weight on this page to correct mistakes, which isn't a great habit. If you mess something up, leave it be - otherwise you'd just be piling on more ink and drawing the viewer's attention to it. Line weight should be used strictly to help clarify the overlaps between forms.

Anyway, jumping over to your vehicle constructions, I feel that despite the issues with the form intersections, many of these were very well done. I especially liked just how solid your basic form-constructions felt. Where your form intersections were flimsy and weak, here you leveraged line weight far more effectively and produced objects that felt firm and solid.

Moving into the more developed drawings, while the proportions on this one were a little odd, you successfully achieved the illusion that the car itself is real and believable, but rather than the drawing being incorrect, the car you were drawing was simply... odd. At the end of the day, developing your eye for proportions will come with practice and time, as you do many studies from observation. What's important right now is that you can construct objects that feel real and believable.

Now, this wasn't always the case - this one definitely tested my suspension of disbelief, but ultimately not every drawing is a winner, and cars themselves are notoriously difficult. The issues presented here however go beyond just bad proportions - instead, this vehicle had a lot of very subtle curves and relationships, and I feel construction was not taken as far as it could have been, and you relied a lot more on guesswork, jumping larger gaps from the structure you had in place to the forms you wanted to add.

We see more of this in later cars, like this one and this vw bus. Remember back to lesson 6, how we explained that curving line can very easily come off as vague. In order to construct a curve that feels very specific, we have to first define it in terms of straight lines, before finally rounding them out. I definitely feel that with a lot of the organic curves in your drawings, you didn't quite define them closely enough, and as I mentioned before, the leaps you made were too great.

That said, the hatchback wasn't too far off, and it did end up feeling quite solid (despite the larger jumps and the strange proportions). You also did a great job of getting really fine details in there, like the grill towards the bottom of the bumper. You captured the sense of depth and form in even these small elements very nicely.

Needless to say, your locomotive, for all the effort you put into it, came out great. I still prefer the aesthetics of the ones where you stuck with blue ink, but either way, the solid construction and bold use of shadow shapes worked out very well.

All in all, you've demonstrated that you're making excellent headway in constructing solid, believable objects, and while you need to work on those form intersections (and perhaps invest more time into each individual form's construction them than you are currently), I am proud to say that you've completed lesson 7, and with it, all of Drawabox's core curriculum. Congratulations.

You can feel free to tackle the 100 chest challenge, but that is entirely up to you.