find the mistke
Shaymaa has been training hard since the last Olympics.

find the mistake
Shaymaa has been training hard since last Olympics.0

for the last

or
since last
the second is better

From 10 oclok to eleven tomorrow I,m going to study English/I study English
ارجو الرد سريعا وبشكل واضح ارجوكم

From 10 oclok to eleven tomorrow I,m going to study English/I study English
ارجو الرد سريعا وبشكل واضح ارجوكم
From 10 o'clock to eleven tomorrow, I will be studying English

هل انت متاكد تماما لانها اثارت خلاف شديد

ارجو التوضيح

حدث سوف يكون مستمر لفتره فى المستقبل Will Be + V.ing

will be studying

Shaymaa has been training hard since the last Olympics
there is no mistake here as since can be followed by the last + occasion or last + period of time and the Olympics is an occasion not a period of time .

There is no mistake in the sentence. It is 100% correct.

From 10 oclok to eleven tomorrow I will be studying ENGLISH