English translation:
tried to ~ but ~
was about to ~ but ~
was going to ~ but ~
Structure:
Verb[ volitional ] + としたが + Result
Verb[ volitional ] + としたけれど + Result
Verb[ volitional ] + としたら + Result
Explanation:
[An action/attempt that requires effort or targets direct goals ・ suggests failure or lack of knowledge about the result.]
I wonder why としたら can be used here since this would be translated as “…if” rather than “…but”
?
Hey 
It comes from another meaning of “たら”, - “when/then”.
So literal translation is “I attempted to/tried to/was about to do X when…”
Is ようとしても another form that means the same thing, as in:
ｍｅｄｉａ ｐｌａｙｅｒで音楽を聞こうとしてもエラーが出てファイルを再生できません。
“I was just about to listen to music, but an error occured…”
Or is it more like “even if I want to listen to music, there’s an error…” ?
Hey 
“even if I want to listen to music, there’s an error…” 
So yes, I could use a more formal “but”, but why would I? Wouldn’t it be best to just use けど since the sentence ends with an informal verb conjugation?
Yeah I’m kinda wondering too. All the sentences use the formal forms けれど or が except one.
Is this just a common way of using the phrasing or would it sound unnatural to use these in a friendly conversation?
They are all acceptable. It’s just that they’re mostly used with formal variants so its better to make it a habit to use the ‘fully formal’ variants rather than the informal. (Which is why we mark it as a hint and not a mistake.)
In the case of たら, there’s no informal way to state what たら states, that’s why its unchanged.
Hope this helps!
