idziemy is a perfective verb while chodzimy is an imperfective verb. Polish has two aspects fro all verbs, one perfective and one imperfective. The perfective usually describes actions that are taking place at some specific moment while imperfective verbs describe habits or generalizations. For example: Idziemy do szkoły = * we are going to school. This is an perfective action as you are going to school in the very moment you say the sentence. The perfective always refers to a specific time. Chodzimy do szkoły = we go to school. As in I attend to school*. This doesn't mean you go to school at some specific time but that you generally go there. To make things more confusing, these two aspects (perfective/imperfective) exist in all Polish tenses and sadly knowing one form doesn't necessarily mean knowing the other, so you can only learn it by heart.
I am not a native speaker of Polish, but at least I am a native speaker of a slavic language.
I think you are confused about what imperfective and perfective verbs are.
Perfective describe finished actions - "I have/had done; I will have done". Besides, perfective verbs have no present tense.
Imperfective verbs describe ongoing actions, that is what you described as "Perfective". - "I was doing; I am doing; I will be doing". Also, imperfective verbs can describe repeating actions.
And I can say that both iść and chodzić are imperfective verbs, and pójść is perfective pair to iść. I doubt there is a perfective pair to chodzić.
Because "idziemy" means "I am going", not "I have gone". "będę szedł" means "I will be going", and "pójdę" means "I will have gone".
If so, what is the difference between iść and poiść then?
Well I am not a native polish speaker, but there are native polish speakers who agree with the same description of verbs, the same that I gave, but more detailed, link: POST
I would appreciate it if you'd give the name of the book you were reading.
I know the difference between iść and poiść, they are both presented in Russian and Ukrainian that I speak. As well as chodzić.
I don't say that your description about the difference between verbs are wrong, they are correct.
I don't want to get you offended, but I think that you use a wrong terminology. Because your description of perfective/imperfective in the comment explaining iść and chodzić contradicts your description of perfective/imperfective in the comment explaining iść and pojść(you also call iść a perfective one in the first explanation, while calling it imperfective in the second explanation).
I am convinced that in your first explanation the right terminology would be determinate/indeterminate(aka progressive aspect vs habitual aspect of imperfective verbs).
How good my polish is? Well I just began learning it, but grammar and vocabulary is really similar to my native language(Russian) and my L2(Ukrainian).
Well being a native speaker doesn't mean good grammar knowledge: When I was in school, I was studying in Ukrainian-oriented school(I am a ukrainian btw), and there were no Russian language class, so even though Russian is my native language, I can't write it properly, and I don't know it's grammar. So I know grammar of any foreign language better than the grammar of my native language.
Just using more literal translation to make it more clear, because slavic langauges(including Polish) have no simple aspect, do they?
A german book? Sadly I don't speak german. Maybe in future I will learn german and read that book. Thanks anyway.
Well I still have that question that intrigues me, what's the difference between iść and poiść then? Also, could you describe determinate and indeterminate verbs?
The correct forms are iść and pojść, with a j. The both forms are perfect example of perfective and imperfective aspects (in Polish: Aspekt dokonany and aspekt niedokonany respectively). If you want to express you are in this very moment going to school, you use the respective form of iść . I can't think of an example where one would use pojść in the present tense, so the following two examples shall be in past and future tenses:
"I was going to school" would use iść, as the action you describe is not secluded (thus imperfective or niedokonany). In contrast to "I went to school" (perfective / aspekt dokonany), where you would use pojść*, since you imply that you have already arrived at school.
I don't know how good your polish is, but this site provdes some further info:
It's more complicated, unfortunately. If 'you are walking' (right now), but there isn't any direction, any goal specified, it's just walking around - it would also be translated as 'chodzić'.
You are walking (around) = Wy chodzicie.
You are walking to the store = Wy idziecie do sklepu.
It may be an overlook... although I think I went through all the sentences that needed it.
Well, I believe that most sentences with 'chodzić' do specify some direction, and thus can only use Present Simple. Only a sentence as vague (or maybe just: as bad) as this one allows for the Continuous interpretation. And those like "We are walking around the park".
Generally, "chodzić" = to go (on foot) and to walk. Present Simple.
"iść" = to be going (on foot) and to be walking. Present Continuous.
If there isn't any destination/direction/goal specified, if it's just walking around, "to be walking" can also be "chodzić". But "chodzić" can never be "to be going".
Then obviously you should recognise that to a English speaker like me, who also speaks German (native speaker) and has studied French for 5 years at secondary school, the explanations are not clear enough. I am still struggling with these two verbs and their use and meaning in sentences.