。
I got a pear for free.
Literal
I [topic-は] pear [object-を] free-of-charge [for-で] received.
無料 ('free of charge, no cost') is a Sino-Japanese compound. で marks the manner/condition. もらう ('to receive') — a core benefactive verb. 梨 is 'Japanese pear' (nashi, Pyrus pyrifolia), round and crisp, quite different from Western pears.