Hello Nachami, I'm a Chinese and English learner. When we learn a foreign language, we can't treat it as if it'd have the same rules as our mother language. (1) 会 as an auxiliary verb, means “there’s a possibility”. It can be used for future tense, present tense, even past tense. i.e. 我不知道他明天会来 (I didn’t know that (there’s a possibility) he will come tomorrow) 我不知道他现在会来 (I didn’t know that he will come now) 我不知道他昨天会来 (I didn’t know that he would come yesterday) It usually can be replaced with 能 or 可以。 i.e. 我明天会来 / 我明天能来 / 我明天可以来。 (2) 会 as a modal verb, it means “can”. It emphasizes the ability of someone. There’s one way to “test” a sentence using 会 as “be able to”. It can be added with intensifiers“很、真、最” For example: 她会唱歌 --> 她很会唱歌 他会开车 --> 他很会开车 Eventually, the context and the intonation in which the sentence said play an important role. Someone won’t say 我会吃 out of anywhere. There must be a context. For example: A: 你几点要吃晚餐啊？(What time will you have dinner?) B: 待会儿我会吃。(I will eat in a minute) Hope they help.

You don't understand because you're understanding it wrong. You're trying to find a word for word substitution. For nouns, yes, that could work; but for verbs, you have to understand its meaning first in order to be able to translate it to English. 会 has to 2 common usages. 1. Expresses one's ability. 2. Expresses one's intention. You were confused about the 2nd usage, that's why I didn't even touch on the 1st one. Let me explain the 2nd usage even more literally. 1. 我明天不会去医院。 I don't intend to go to the hospital tomorrow. Now, from my translation, you tell me, in English, is that a "won't" or "can't"? If you wish to express "I won't go", you say "我不去"。 If you wish to express "I can't go", you say "我不能去", "我没办法去"， "我去不了" Now, do you need me to explain "2. 他今天晚上会来吗？" as well?

其实汉字难就难在此，一个字有很多意思，我把会所有的意思给你整理了下，你看下就明白了 ◎ 聚合，合拢，合在一起：会合。会审。会话。 ◎ 多数人的集合或组成的团体：会议。开会。 ◎ 重要的或中心的城市：都（dū）会。省会。 ◎ 彼此见面：会面。会见。 ◎ 付钱：会账。会钞。 ◎ 理解，领悟，懂：会心，体会。 ◎ 能，善于：会游泳。会英语。 ◎ 时机，事情变化的一个时间：机会难得。 ◎ 一小段时间：一会儿。 ◎ 可能，能够：他不会来了。 ◎ 恰巧碰上：会其怒。 ◎ 为祭神而组织的活动：香会。 ◎ 应当，一定：长风破浪会有时。 ◎ 古同“绘”，五彩的刺绣。 ◎ 总计：会计（ａ．管理和计算财务的工作；ｂ．管理和计算财务的人）。 ◎ 姓。

1. 我明天不会去医院。 I'm not going to the hospital tomorrow. 2. 他今天晚上会来吗？ Is he coming over tonight? 会 here, expresses the person's intention of doing something. Of course, take example two for instance, one could also say: (他今天晚上会来吗？) 1. Will he come tonight? 2. Can he come tonight? Both are acceptable and fine, but those are not as literal a translation as the ones I provided.

Thank you Jove Cao, this is very helpful!