Translation:The weather is not good this month.
- good; excellent; fine; nice; pleasant; agreeable
Usually written using kana alone
[Edit to add: Writing words in kanji that are not supposed to be written in kanji may be a stylistic choice, but as a learner, it may often signal to a native speaker that you don't understand the proper usage.]
I guess you could say something like よくない天気が続いています (yoku nai tenki ga tsuzuite imasu) to say "the weather has not been good", but it's literally saying "the not good weather is continuing" so it's pretty interpretive and probably not that helpful a suggestion. I feel like any translation of this sentence trying to catch the nuance of a tense that doesn't exist in Japanese is going to run into the same problem, but I'm interested to hear any other suggestions because I have a tendency to think very literally.
Yes, you do. It is considered more formal but is used in writing and is correct and quite a common character. It tends to be used more for yoi than ii because it implies more formality, that's all.
For example, if you check the headline of this article from the Asahi Shinbun, there it is.
It's pretty common IMO.
I have downloaded a few apps for kana and kanji on my phone for fun, but usually I just practise/learn by reading and writing. I also have an excellent kanji book and a sanseido waei dictionary (Japanese to English). I would recommend waei dictionaries as it gets you thinking in a Japanese mindset and helps you to learn the rank order of kana which is important for conjugating.
I don't think English speakers say "is not good" for a period as long as a month. "Has not been good" or "will not be good" or "The forecast is not good" but not "The weather is not good". Duolingo doesn't take "Has not been good" or "will not be good" though. Is this just a bad translation and it should take one of those, or am I missing something specific to the meaning of this sentence that makes it that awkward to translate to English?
The course contributors don't normally monitor old threads, they check the error reports. Did you submit one? Or was this a question where you couldn't submit one? If that's the case, then it was probably a "type what you hear" question. Duolingo was designed to only accept one "correct" answer for those kinds of questions, even though you can write the same thing in Japanese in many different ways. The contributors are aware of the problem, but as there is no fix yet, you either have to memorize the correct combination of kanji and kana for those questions or use the word bank.
They're related, but not interchangeable. -i adjectives in Japanese act like verbs and change form to show tense and negation. 良く (normally written as よく) is the negative "conjugation" of いい.
いい (ii) - good
よくない (yoku nai) - not good
よかった (yokatta) - was good
よくなかった (yoku nakatta) - was not good
*いい (ii) is a casual form of the word よい (yoi), which is where the よ (yo) comes from in the other forms.