Mother, father, 2 granfathers and 2 grandmothers, you just highlight from which side
Now comes real fun.
Father's family: brother(uncle- hrv. stric), sister(aunt - hrv. tetka). Spouses: uncle's wife(hrv. strina), aunt's husband(hrv. tetak)
Their children: my relatives, simple version - hrv. bratić(male, singular) i sestrična(female, singular) for both father's brother and sister children.
That's how we say it today, but Croats in Bosnia and Herzegovina still use real proper words like: children of father's brother - stričević(male), stričevićka(female), ie children of father's sister: sestrić(male), sestrićka(female).
My father and mother say: nephews, hrv. nećaci(plural), nećak(male, singular), nećakinja(female, singular).
Mother's family: brother(uncle - hrv. ujak), sister(aunt - hrv. tetka). Spouses: uncle's wife(hrv. ujna), aunt's husband(hrv. tetak).
Their children: today's version is like I said bratić and sestrična as my relatives, but real is: uncle's children - ujaković(male, singular) and ujakovićna(female, singular)...... aunt's children - tetić(male, singular), tetićka(female, singular).
My mother and father say: nephews, ie hrv. nećaci(plural), nećak, nećakinja(male, ie female both singular)
It's not that hard. You can notice some words go exactly like in Spanish and Portuguese language like tío and tía, subrino and subrina. The only difference is that last letter and fon, because we have cases and genders in our language.
"Ein Trainer sehen, was passieren in Platz. In diese Spiel es waren zwei, drei oder vier Spieler, die waren schwach wie eine Flasche leer!"