In most cases it would be considered improper. Try rephrasing the sentence, for example: Her favorite colors are red, white, and blue. But she also likes gold. You could change the second sentence to: Also, she likes gold.
His name started from the letter N. This is a sentence starting from the word His.
No, "suddenly" is not a complete sentence. It is an adverb that describes how an action is performed in a sentence.
he started to accelerate.
The business was started by an entrepreneur.
I started to swirl around
The rabbit dug a burrow underground to seek shelter from the rain.
After I took my medication, i had started to hallucinate.
Example sentence - I heard the thunder before the rain started.
She was so scared that she started to tremble.
The FBI started their investigation.
The dead deer started to decay.
At the park, I started swinging on a branch.