Can a person start fasting six days of Shawwaal when he still has days to make up from Ramadaan?

If a person fasts six days of Shawwaal after Ramadaan when he has not
yet completed the Ramadaan fast because he did not fast ten days
ofRamadaan for a legitimate reason will he have the same reward as a
person who fasted all ofRamadaan and followed itwith six days of
Shawwaal, i.e. will he be like a person who fasted for a lifetime?
Please explain to us, may Allaah reward you with good.
Praise be to Allaah.
The precise rewards for the deeds which people do for the sake of
Allaah issomething which is known only to Allaah. If a person seeks
the reward from Allaah and strives to obey Him, his reward will not be
lost, as Allaah says (interpretation of the meaning):
"We shall not make the reward of anyone who does his (righteous)
deedsin the most perfect manner to be lost." [al-Kahf 18:30]. If
someone has missed some of the days of Ramadaan, he should fast them
first, then fast six days of Shawwaal, because he cannot follow the
fast of Ramadaan with six days of Shawwaal unless he has completed his
Ramadaan fast.
And Allaah is the source ofstrength. May Allaah bless our Prophet
Muhammad and his family and companions, and grant them peace.
Fataawa al-Lajnah al-Daa'imah,