This is the 13655th most frequent Polish word.
pociągami
"Pociągami" means "by trains" in English.
Here, "pociągami" is used as the instrumental plural form of "pociąg" to express the object of interest in combination with the verb "interesować się".
Interesuję się pociągami jako hobby.
I am interested in trains as a hobby.
In this sentence, "pociągami" is the instrumental plural form of "pociąg", indicating the object involved in play.
Dzieci bawiły się pociągami przez całe popołudnie.
The children were playing with trains the whole afternoon.
The word "pociągami" is the instrumental plural form of "pociąg" and is used here to indicate the means of transportation.