The speaker of 'Break, Break, Break' cannot—

The speaker laments: 'And I would that my tongue could utter / The thoughts that arise in me.' This expresses his inability to speak or express his thoughts and grief in words. He can see (ships, boys, sailor), hear (sea breaking, songs), and feel (grief deeply). What he cannot do is articulate/speak his profound inner emotions. Hence (3) speak is correct.