Dought & clear, - 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 of
Ramadaan for a legitimate reason will he have the same reward as a
person whofasted all of Ramadaan and followed it with six days of
Shawwaal, i.e. will he be like a person who fasted for a lifetime?
Please explain to us, may Allaah rewardyou with good.
Praise be to Allaah.
The precise rewards for the deeds which people do for the sake of
Allaah is something 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) deeds
in 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 of strength. May Allaah bless our Prophet
Muhammad and his family and companions, and grant them peace.