The pronoun to can be used in copula-type clauses to connect subject and predicate, ie. it can be used instead of the verb to be to express equality.
Just as dzieci są małymi ludźmi means ‘children are little people’ (notice that the predicate, little people, is in instrumental, małymi ludźmi), so does dzieci to mali ludzie (but here the predicate is in familiar nominative).
There is no similar construction in English, so you should just remember that to can be usedd instead of to be verb to equate two nouns. And it is independent on gender and number, eg. córki to dziewczyny (daughters are girls), jabłko to owoc (an apple is a fruit) – so it is actually simpler than English, where you would use is or are, depending on number.
Your tables say "except for male persons" (more specifically: groups of people with at least one man, and surely 'people' are such a group), and you have a few sounds that are softened, enumerated... but it misses Ł turning into L. Generally, the masculine personal plural version of adjectives/possessives is usually different from the other variants.
What a shame there are no more explanations for the lessons, just exercises. This is the perfect learning system for this language, as far as i'm concerned. I've tried several times to learn Polish and not got far because the system didn't suit my mind. This one is systematic and has the right steps, addressing the language in grammatical building books, not in a tourist approach ("can i book a hotel room for two people please... where is the post office?") or all-of-life-in-one-go approach (i have two books on the desk and lots of flowers in my garden..."). I almost gave up when the explanations stopped and i struggled to find quick but orderly answers to my queries on declension, adjectives, plurals etc. But i have found the answer here! https://end.translatum.gr/wiki/cz%C5%82owiek Click on "main page" (top left) then insert the key word (it helps if you know the nominative singular) and lo and behold, you get a little lookup table with all you need to know. So then it's easy to understand the progressions in the exercises that seem haphazard without the key. Good luck and lots of fun, everyone!
I am sure there is a long explanation describing evolution of Polish language, and other with groups of letters put in tables, but
-ry ending changes to -rzy - ły changes to -li
you can read page 38-39 here http://www.mediafire.com/view/s2uuu1gp0wgv9pp/PolishGrammar.pdf
Adjectives have different gender-forms corresponding to the genders of nouns, as well as a full set of case endings in both singular and plural, except for the Vocative, which is always like the Nominative. An adjective agrees with the noun it modifies in gender, number, and case. The masculine singular ending is -y, as in dobry (good), ładny, (pretty), miły (nice, kind). This ending is spelled -i after k and g: wielki (great), drogi (dear, expensive); and after soft consonants (which are not common): tani (stem tań-) (cheap), głupi (stem głup’-) The feminine singular ending is -a, as in dobra, ładna, miła. The neuter singular ending is -e, as in dobre, ładne, miłe, spelled -ie after k and g: wielkie, drogie. This is also the plural ending for adjectives modifying nonmasculine personal nouns. The masculine personal plural adjective ending is -y/i, before which a hard-to-soft consonant change occurs: dobry dobrzy, ładny ładni, miły mili, wielki wielcy, drogi drodzy; for more illustrations see further below.
rz, cz, sz, ż, are followed by y, never i
If C is followed by Y, then it makes a "tsy" sound. If it's followed by "i," then it makes an English "chee" sound like "cheese," or the Polish Ć sound.
If dz is followed by Y, then it makes a "dzy" sound. If it's followed by "i," then it makes an English "gee" sound like "Jesus" in English, or the Polish "dź" sound.
dzieci - to przyszli kudzie.
-- Janusz Korczak