Other contributors have said "How verilog is efficient over vhdl?" is the same question as "What is the Difference between verilog and vhdl language?" If you believe that these are not asking the same thing and should be answered differently, click here
What is the Difference between verilog and vhdl language?
"a" is an indefinite article. The English rules for when to use the indefinite article and when to omit it are complicated, and are usually learned by experience.
Linguistics is the scientific study of human languages. Linguistics can be broadly broken into three categories or subfields: the study of language form, of language meaning, and of language in...