Is it okay to have these two requests without any joining part, and is this the standard way of expressing it or is a particle being omitted?
"te" basically acts as the "joining part" so yes, this is correct.
Wanted to ask the same thing
also (asking for any japanese speaker)
do people ever write this with a 「て、〇」 or is it just 「〇て〇」？
I suspect a comma is a natural thing to use between the two requests, but that is lost since we don't get commas in the tiles. I do not know if a particle can be used instead, or whether the sentence is gramatically correct without the comma.
Or at least それから.
Only if you want to specify "please do this, AND THEN do this".
Duo's sentence does not ask you to fulfill the request in a certain order.
Some nouns (like まど in this case) are separated into their kanas in the given word-cards in these types of exercises. Is this intentional?
て does the "and" function
What's turn off in Japanese then?
消す 「けす」to turn off; to erase
There should be a comma or conjunction like それから
It doesn't accept 付けて for some reason. Is that just Duo being Duo or is the kanji incorrect?
In this sense it's usually written 点けて or in kana.
can't i use そして after 窓をあけて?
Why put a little harmless と made my whole sentence wrong? I wrote 窓を閉めてと電気をつけてください
と is used when listing nouns and cannot be used to link clauses as you have it
The て form of the verb 閉める・閉めて is the connective "and..." in this sentence