"Where is the modern phone?"
Translation:Cái điện thoại hiện đại ở đâu?
The first is used for a bunch of singular objects like a cake, a vehicle, a single shoe, a single chopstick etc. while the latter is a generic classifier/counting word that covers most of the other ones. Do keep in mind that you can also attach cái before another classifier/counting word to add emphasis like in the sentence: "Cái tấm hình này bạn chụp hồi nào?" (When did you take this photo?).
Thanks for the detailled explaination. Much appreciated, it s now more understandable for me
In Vietnamese. sometimes use "chiếc" and sometimes use "cái". But "cái" is more popular than "chiếc".
But there are times when it acts as a symbol instead of a noun. Example: "Có bao nhiêu chiếc xe? - (count) Một chiếc, hai chiếc, ba chiếc ..."
Other Example: "Có bao nhiêu cái bánh? - (count) Một cái, hai cái, ba cái ..."
I see in many phrases nặng tone is prevailing. Is it a pure coincidence or is it really so?