"Er sieht den Bau."
I think "construction" is fine; construction site would be "Baustelle", don't you think?
Does this mean that the sees a construction/building, or something being constructed/built or is this interchangeable based on context?
I believe it could be both, a building in progress or a building that has already been finished.
To see is a non-progressive verb, meaning you can't switch 'see' with 'seeing' like you can with 'eat' for example
So can anyone tell me how you would use Bauen as a command in Second Person informal?
I thought you just dropped the -en so it would become "Bau", the same as 'construction' Seems confusing
Yep, 'Bau jetzt!' or 'Baue jetzt' would be 'Build now'. It's not necessarily confusing, many words in English and German are both nouns and verbs depending on usage...
Can someone please explain why is becomes "den" Bau? I don't fully understand this! Thanks
Bau is in the accusative case here and for 'der' words, that changes to 'den'. And don't worry, all this will slowly come and become second nature. But it does mean you have to learn the der/die/das and plural with each noun. It sounds a pain, but in the long run it really helps.