Medina said it very well. "Lügen" is very general, you can say for example "Mein Nachbar lügt zu viel." (my neighbour lies too much), but if you want to talk specifically about lying to a person, you would say "Ich lüge dich an", oder "ich belüge dich". (I lie to you). The meaning of these two sentences is the same, as you see, you just use different grammar depending on which one of the two you use. I hope this makes sense.