'it is quite unclear' is correct and usable in written English. You can use this phrase when you want to express that something is not easily understood or clear. For example, "Although the instructions were provided, it is quite unclear how to properly use the product.".
Later, he watches a crude porn film on TV, and it is quite unclear whether the next scene is a dream or waking reality.
It is quite unclear how the government would pay for a comprehensive program, and no candidates seem eager to discuss ways to hold down health care spending.
Thompson, in fact, will not have a journalism role at the Times; so, it is quite unclear how Sullivan's mandate reaches him.
Despite the lack of a democratically elected regime in Syria prior to the present civil war, it is quite unclear to me why the anti-Assad uprising in Homs was immediately assumed by the west to be the onset of a democratic revolution for the Syrian people.
"It's quite unclear … On the one hand, many security analysts reckon that the Brotherhood is not actively encouraging political violence from the leadership level, but on the other the suspicion has been raised that a lot of Brotherhood supporters or even members may be involved in political violence, with the leadership turning a blind eye, or unable to do very much about it," he said.
But it was quite unclear who could make the decision about that.
Though it's quite unclear that her strategy would be any more effective than Barack Obama's, though it sounds tougher, and her inclusion of a Syrian no-fly zone to stubbornly try to bring down the Assad regime overlooks the stark reality of a strong Russian air force presence in Syrian skies.
Thanks to Ludwig my first paper got accepted! The editor wrote me that my manuscript was well-written
Listya Utami K.
PhD Student in Biology, Bandung Institute of Technology, Indonesia