Not only he studies English, but he also studies German.
NOT ONLY DOES HE STUDY...
Barely Annie had finished reading when the lights went off.
BARELY HAD ANNIE FINISHED…
I visited a gothic castle which it was built 600 years ago.
WHICH WAS BUILT / BUILT (reduction)
It was after eating a sandwich that Sam experience a sudden pain in the stomach.
EXPERIENCED
Oh, but I did got you a birthday present. Here it is!
I DID GET YOU
Mark is very patient, his brother is short-fused whereas.
...,WHEREAS HIS BROTHER IS SHORT-FUSED.
At no time was allowed the students to cheat.
WERE THE STUDENTS ALLOWED…
Only if you study hard you will pass.
WILL YOU PASS
Even although it was a roasting hot day, we decided to stay indoors.
EVEN THOUGH/ALTHOUGH/THOUGH
However I love Coca-Cola, I don't drink it very often.
ALTHOUGH/EVEN THOUGH I LOVE…
Despite it was raining, we went out.
DESPITE THE FACT THAT/IN SPITE OF THE FACT THAT IT WAS RAINING
In spite the high temperature, she felt extremely cold and shivery because of a bout of flu.
IN SPITE OF THE HIGH…/ DESPITE THE HIGH…
Only when I got home I realized I'd lost my keys.
DID I REALIZE
Boredom is a distressing experience; such as, it has a negative impact on work and learning.
AS SUCH
On the other hand, I really ought to cut down on the amount of carbohydrates I eat, but on the one hand, I simply can't resist potatoes, rice and pasta.
ON THE ONE HAND, I REALLY…ON THE OTHER HAND, I SIMPLY…
Little she realized the danger she was in.
LITTLE DID SHE REALIZE…
Neither Fred or George has ever been very confident about their appearance.
NEITHER…NOR
It's crucial for me to speak accurately, but I can only so do thoroughly by studying the grammar.
DO SO
I have managed to save a deposit for a summer holiday, despite of all the other expenses I've had to meet.
IN SPITE OF/ DESPITE ALL THE…
Jessica hasn't done her essay and Sean hasn't too.
EITHER
I had known about the problem, I would've helped you.
HAD I KNOWN