Translation:I miss my older brother, I want to see him at once.
I don't know why your comment was down voted. "At once" is not natural in this context and is hardly used nowadays. While "immediately" is slightly better, it is still a bit awkward. Most natural way to say this is "I want to see him right now" or "I wish I could see him right now."
Chinese native speakers:
Apart from the pause, is there any way to distinguish this sentence from "I think my older brother wants to see him right away"? Is this a legitimate interpretation of the Chinese?
Edit: The answers below now suggest both that my alternative translation is a legitimate interpretation and that it isn't. I'll go with "is", since it's the same person saying both yes and no, and the dictionary says yes. ;-)
I'm not sure why that should be assumed, versus "想" simply meaning "think", given that Collins gives the example "我想他会同意的" ("I reckon he'll agree"), which is why adding "念" was my earlier suggestion to clarify Duo's sentence, but you're the native speaker, so I'll take your word for it.
(Collins translates "想" as "reckon" for that example, but "reckon", as opposed to "think", is mostly British, and is common only in certain limited regions in North America.)
Collins also gives "我想换个工作" as "I want to change jobs", and there's no "要", so putting the two Collins examples together seems to me to make my initial suggestion quite plausible, but again, you're the native speaker, not I.
It seems I can only reply here. It helps to think of it as an idiom, so it is not something strictly logical but unique to the language， in a way. Or just something to remember. The "logical" meaning, would be the one you gave from Collins dictionary, which is correct as well. Duolingo likes to teach more colloquial language sometimes, which is how people speak so it is a good thing.
I wrote “I miss my older brother. I want to see him Immediately.” DL failed me. I guess “immediately” is too much of a mouthful. As one student wrote : “DL is too picky and frustrating!” Not only that, it is also inflexibly dictatorial. That is, if you don’t adhere to DL’s version, then you can’t progress. There is more than one route to the apex of Mt Everest.
Yes, though "to be right back" is a particularly idiomatic turn of phrase, and to be able to generalize and apply "马上" in its full range of contexts, it's usually easier to think of it as "right away" (and so "we'll be back right away" is another way to translate your sentence).
The problem here is that unless this is said by a little kid throwing a tantrum temper not something useful for a learner practically. There are more commonly encountered daily situations where "马上/immediately/right now/at once" would be used. If this was placed situationally say in an "upset customer" scenario it would be much easier to digest. Learning is relating so we need a scenario we can easily imagine.
Chinese "ta" always sounds like "t-ha" to my ears. I mean not like the English "th" sound but like a "t" sound and a "h" sound before an "a." The difference between Mandarin Chinese "ta" and "da" is that "da" doesn't have that "h" sound there. (More scientifically put, it's not aspirated.) However, I don't think it ever sounds like only "ha."
True, and I think some speakers (perhaps regionally) tend to exaggerate the aspiration, especially in "ta", but also in at least some other syllables with a "t" initial.
But you're right, "ta" never gets pronounced "ha". That could be a recording or speaker quality issue, though I hear the "t" when I play the sentence on this page.
"Right" doesnt need to be in this sentence: I miss my older brother and I want to see him now. When? Right NOW!