"I need to go to the shop in the afternoon."
Should be accepted, it's also correct. But it still hasn't been updated :-/
to be fair it's much better than the korean and japanese trees, and they created it in only one month or so... chapeau
When you hover over the word 'need' in the sentence, the hint gives you 需要, but if you write it in the answer, it's turned down and the correct solution should only have 要. Then either the hint or the 'correct solution' is wrong.
Me neither. I tried asking a Chinese friend, and he couldn't really explain it either. But that's like most languages, isn't it? When you speak it as a native, you just "know" what sounds correct without knowing the grammatical rule/idea behind it.
"need to go" can also be "必須去”； “要去” can be "need to go," though it is just as (or even more) likely to be "want to go" or "will go“
Chinese grammar puts time components first. The sentence could begin with "I" or 我 (the subject), but often the time clause comes before the subject as it makes sense to put the subject next to the action: 我要去。
我要去商店 means "I need to go to the store" or "I will be going to the store", while 我去商店 means "I go to the store" or "I am going to the store."
我要去商店 is I want to go to the shop; 我去商店 is I go to shop. 我去着商店 is I'm going to the shop