as some people mentioned here before, "on" and "in" often change between noewegian and english. so even though you say "i" it could mean "on", i assume you get it from the context.
I'm not a native English speaker but I think in this case "in the tree" is the way to go: I imagine you could see a tree as a collection of branches, leaves etc and if the outer leaves mark the "boundary" of the tree, chances are the bird will be somewhere inside that "box", thus IN the tree (unless it sits on the very top branch of the tree I guess). It's the same in Dutch by the way as we say "de vogel zit in de boom" (although that may not help you hehe ;))
If you're sitting on a tree (e.g. you're a lumberjack and are having a break) I think you'd say "han sitter på et tre".
US English speaker here, you are correct. If you said you were sitting on a tree, I would assume that the tree has fallen down and you were sitting on its trunk.
This is how I use in/on for trees in English:
If something is part of the tree, such as leaves, fruit, or acorns, then it is on the tree.
If something is not part of the tree and is within the branches, such as an animal, person or a tree house, then it is in the tree.
However, if something is on the trunk, not in the branches, then it would be on the tree.
For example, a birdhouse can be on the tree (trunk) or in the tree (within or hanging from the branches).
It's not very clear in the pronunciation here on this site, but you're supposed to hear a little "eh" at the end. /treh-eh (treet) instead of just treh (tre)/
What does this mean anyway? The bird is inside the upper part of the tree?
In English "up in a tree" is just an alternative way of saying "in a tree", sitting on a branch of a tree. It emphasizes that it's above the speaker (for example, you wouldn't say it if you were in an airplane looking down!), but it does not necessarily mean that it's in the highest part of the tree.
When it's the fast voice, it sounds like 'Fugl mer' I assume that's the right pronunciation?
I'm afraid not. 'Fugl-n er' sounds much like 'fugl ner' or 'fugl mer' as you are hearing. Hope this helps.
Would "Fuglen er oppe treet" be equivalent? In other words, can we remove "i" and have it still be correct?
It's a definite form of 'et tree'. You'll find more about it in the Definites lesson :)
"Er" can be used like "is" in English? As in, someone or something is located somewhere? I'm getting confused.
I think, that "er" mean "is". But, we do not use it with the verb, like: "Jeg spiser et eple." We use it with the location: "Et eple er på bordet." and with the easy sentences like: "Det er ikke et eple." I hope I help you and you are not more confused. :-) Sorry for mistakes, but I am not native speaker. :-)
Would "Fuglen er i treet" be the same, or would that imply that it is actually inside of the tree? I feel like saying the bird was actually inside of the tree would be "Fuglen er inne treet"
We farsi speakers have problem pronouncing TH in english so three and tree r the same for us. I think Norwegians do too :p