Some independent usages of "olmak" and "etmek" 

Beside their auxillary functions, these verbs also have independent usages.

1. "Olmak" on its own may mean "to ripen, to be ready to eat [for fruits] , to become mature "

Bahçedeki  elmalar oldu. ---> The apples in the garden are ready to eat.

2. "Olmak" on its own may mean "to be at somewhere " 

Saat 5´te orada olacağım. ---> I will be there at 5 o´clock.

3. "Olmak" on its own may mean " to happen "

Ne oldu ? ---> What happened ?

Ne olacak --> What will happen ?

Dün bu yolda bir kaza olmuş --> [I heard that] There was an accident on this road yesterday.

                                             [I heard that ] An accident happened on this road yesterday.

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"Etmek " on its own may mean " to worth, how much in total "

Bu telefon 100 lira eder. --> This phone may worth 100 lira.

Kaç lira etti ? ---> How much did it come [total] ? 

                          [Imagine, you are buying several things from a shop, you want to know how much you need to pay , asking to shopkeeper " How much is the total ? ]

"Etmek" on its own  may just mean " do " 

Etme. kıyma bana ! ---> Please don´t do , spare me ! 

Ah bir bilsen, bize neler ettiler !-> Ah  If only you knew what have they done to us !

Anlat bakalım ne ettin İstanbulda ? --> Come on, tell us what have you done in İstanbul ?