If someone asks me how something is or how I am doing, for example if someone asks me "wie geht's?" Is it okay to respond with "alles gut" or should I say "Alles ist gut?"
Doesn't really matter, there are several options and as those are short, daily phrases, no one expects you to form out lengthy sentences. However, it is common to thank and to ask how the other person is doing:
Danke, gut, und Ihnen? (more formal)
Danke, gut, und selbst? (less formal)
Just observe what other people say, as there are regional customs.
maybe "Schlecht", but short as "Gut" is the common answer
I thought about these possibilities:
- mir geht’s gut, danke!
- mir geht’s so-und-so, und dir?
- mir geht’s schlecht, und dir?
- mir geht’s prima, danke!
But I am not a native speaker! I hope these are ok.
You say "Gut". And to ask them back you are to said " und dir". Some say "und ihnen". It is depend on how you want to respond.