This construction consists of the word нљт in the meaning 'there is no...' or '[one] doesn't have...' The past tense of this construction is нљ было, and the future is не бџдет. Note that these sentences are impersonal, i.e. they have no subject. Hence the neuter Singular forms of the verb, было and будет.
Нљт рџчки (Gen.). There is no pen.
У менї нљт рџчки (Gen.). I don't have a pen.
Нљ было рџчки (Gen.). There was no pen.
У менї нљ было рџчки (Gen.). I didn't have a pen.
Не бџдет рџчки (Gen.). There will be no pen.
У менї не бџдет рџчки (Gen.). I won't have a pen.