What is the duty of brothers towards their paternal half-brothers whom a language barrier prevents from good understanding and communication, and is it sufficient to contact them only on the two Eids, in Ramadan, and on special occasions?

Maintaining kinship ties is obligatory, and severing them is forbidden. Kinship ties are maintained by anything customarily considered a connection, such as financial assistance, fulfilling needs, visiting, and exchanging greetings through correspondence. Contacting siblings on occasions is sufficient to avoid severing ties, while more connection is better and brings greater reward and blessing. Language difference is not an impediment.