Greetings from level 2 (absolute beginner) … I would like to know how to read context sentences. For example:
一人でカラオケにいきました。
According to any online japanese dictionary (nihongodera, jisho… etc.), I get this:
ichi nin de karaoke ni ikimashita
But… shouldn’t it be hitori de karaoke ni ikimashita?
I am lost 
Both readings for 一人 are correct, what will change here is the context and the particle that coems attached to it. In the sample sentence で is being used, and so conveys the “way in which someone went to sing a karaoke” and in this particular case hitori is the correct reading as it represents how the person went to karaoke, in this case “alone” the person went alone.
Some more samples you can find here: JLPT Sensei
And some more discussion here: italki
That was my take on it, maybe someone else could also verify 
Happy studying and welcome!
Yes. What part of Jisho is telling you otherwise?
While いちにん is hypothetically a valid way of reading 一人, there are very few circumstances in which it would be expected by a listener. Best to stick with ひとり.
いちにん is a valid reading, but I’ve only ever seen it as part of certain words, like 一人前 (いちにんまえ, “adult”) or 一人称 (いちにんしょう, “first-person”). It’s almost always gonna be ひとり. If you search “一人” in a dictionary and scroll through all the entries that start with it, you’ll see that the vast majority of them only have ひとり, with only a few that have either いちにん or both readings (and one that’s different)
Have you tried ichi.moe? How about DeepL (listen to audio) and Google Translate?
In any case, all websites use computerized parsing so it’s prone to error. You aren’t asking a human.
This is an unfortunate side effect of WK not putting furigana on their context sentences. I’d suggest searching those words you don’t know yet (like 一人) in the WK vocabulary first, as then you’re likely to find the correct reading a bit quicker. In this case, the parsing is:
一人で カラオケ に いきました。
But jisho gives the correct reading for 一人 as hitori and is usually correct, so don’t worry about this too much. I have no idea what nihongodera is, but if that gave you ichinin I’d stop using it.
oh I see! I never put in the whole sentence. I don’t understand why that matters so much, that’s really unfortunate.
Maybe one tip would be since it didn’t show 一人 as a clickable word, sometimes the results are different if you just search for that word on its own. So if you search just for 一人 or 一人で it shows the correct reading and a dictionary entry. So in general if I’m really lost on a word I might search for slightly more or less characters around it or use the * wildcard to widen results.
For verbs it can be tricky, normally it will suggest the root verb, but you can also search for just the kanji followed by a star *
You’ll quickly get better at parsing the sentence (what is a word vs what is a particle) and just searching for those on jisho. It doesn’t always work out, and sometimes you have to google it or use deepl or a forum to figure out what the root word is, but it gets easier over time!
Because it assumed it’s an on’yomi compound. Full sentence searches in jisho are not guaranteed to give you correct, context-relevant readings.
