Liczebniki (part 2 & 3)

Today we'll take a look at ordinal and collective numerals.

Ordinal numerals are simple and user-friendly. They act like adjectives, so once you should have no problem, once you've learnt the main form of the numeral.
Collective numerals are a bit more complicated. When it comes to them, there's a few things you have to remember:
a) form
b) the three categories of nouns you count using these numerals
c) declension
d) agreement with the noun (i.e. the case they require for the noun that follows them).
They may not be pretty, but the good news is that once you've figured out the mechanism, you won't have any problems, not to mention that you won't actually be using these numerals very often.

Notes on the use of Instrumental

This post is also a response to the comment on this post.
After consulting the books, here's my attempt at making things easier to understand.
First of all, I totally agree with Biluś - with those endings (końcowki) you don't have much of a choice, with or without further explanations about grammar. You learn them by heart, and after a while you'll forget all about the ordeal you've gone through. In this way, you will be able to recognize the Instrumental case, and all the others, just by taking a look at the ending. However, if you want to build up your own sentences and are not sure when and how to use it, maybe this will help:

One of the main constructions requiring Narzędnik (Instrumental) has the following structure:
Kto jest kim
Co jest czym
(Subject) jest (predicative)

In Polish, the subject (kto / co) is in Mianownik (Nominative), whereas the predicative (kim / czym) is in Narzędnik. Let's take a look at your examples:
Marek i Piotr są studentami Politechniki.

• Marek i Piotr: Subject (Mianownik / Nominative)
• studentami: predicative (Narzędnik / Instrumental) - this gives us further information on the subject of the sentence, and it follows the pattern (subject) są (predicative)

Let's take another example:

• On jest Francuzem / lekarzem / studentem.

It is easier if you ask the questions:
Kto to jest? and your answer will be "On" (Mianownik)
Kim on jest? - this gives you further information about profession, nationality etc. and your answer will be a noun in Narzędnik.
It may be that the noun is determined by an adjective - like in your example: Oni są dobrymi przyjaciółmi. In such a situation, the adjective will also be in Narzędnik. You have to pay attention to the fact that even if the cases are different, there is still agreement in gender and number. You can't say, for instance, *Oni są (plural) dobrym przyjacielem (singular).

Finally, some tips and tricks:

1. look at the verb. Narzędnik mostly occurs after these verbs: być, bywać, zostać, stawać / stać się, okazać się, zrobić się.
2. look at the subject of the sentence and then at the nouns or nouns + adjectives giving you further information about the subject. They will most likely be in Narzędnik. Note here that if you have just an adjective, without a noun, describing the subject, then you have full agreement - gender, number and case. There is a difference between Marek jest zdolny and Marek jest zdolnym studentem. And don't forget to ask the questions. In the first situation, the question will be Jaki jest Marek?, whereas in the second situation, the question will be Kim jest Marek? (On jest studentem - this is the essential information, and the adjective describing "studentem" will obviously be in Narzędnik).

Hopefully, this will clear things up a bit (and remember that Instrumental has many other uses and specific prepositions. If you need any help with those, let us know).
Powodzenia!

Learning the cases

This post is in response to anonymous' comment on this post. I'm assuming my own lack of a grammar foundation here - I was never taught the mechanics of grammar and, in order to learn Polish, I had to learn what the different parts of speech actually do - even down to adverb/adjective... so, I sympathise, anonymous!

My esteemed przyjaciółka, Sam, will be able to help explain more than I can about why the instrumental is used in the particular example you give: 'Marek i Piotr są studentami Politechniki. Są dobrymi przyjaciólmi, chóć kazdy jest inny'

However, this was my strategy for being able to 'spot the case' in an exam I sat last year - it's a very old technique of learning: by rote - but it worked like a dream, so I pass it on in the hope that it might be useful to you, too. 

Print the following documents, which are (arguably) the most important cases and their endings: 

• accusative, genitive, instrumental table
• blank accusative, genitive, instrumental table

Look at the completed table and test your memory of it - then try to write the endings out from memory in the blank tables. I guarantee, you make yourself do this over the course of a week, you'll remember. Good luck!