use them as usual
to = الى
for example
i went to the hospital
for= لأجل
this gift is for u
of = تستخدم للإضافة
the button of the dress
this is the easiest usage of them but there are a lot of things u have to know and memorize
for example , there is something called Phrasal Verb in which u have to memorize the verb and the prepostion after it
example , take care of him
أهتم به
but people may say take care by him or for him and this is wrong
for more info visit this site
http://www.englishclub.com/vocabular...verbs-list.htm
another thing (
to ) is used in another way like
i want
to drink something
here TO is not a prepestion but it's the infinitive TO and it means in Arabic
أن المصدريه مثل اريد
ان اشرب اريد
ان اذهب الخ
i think it's enough for u to know that coz there is another thing but i don't know what to call it i think u don't need to know it now coz they always use to but it in TOEFL exams
good luck
ya , by the way , put the logo in ur signature coz u r a member in Only English group