In general the simple present expresses events or situation that exist always, usually, then exis now. Have existed un the past and probably will exist in the future. It is used for general statements of fact.
Structurre :
(+) S+V2+O+adv
(-) S+did not+V2+O+adv
Example
(+) I Studied management yesterday
(-) I did not study management yesterday
Note :
Verbs:
. Reguler : Study Studied Studied
. Irreguler : Go Went Gone
Adv:
. Yesterday
. Last week, last night, last ...
. .... a go
. Etc ...