Present Perfect vs Past Simple
Past Simple
Present Perfect
100

Mary has travelled/travelled since she graduated high school. 

has travelled

100

She + to have 

she had

100

she + to have

she has had

200

Before lunch, he has had/had a snack.

had

200

they + to study

they studied

200

they + to study

they have studied

300

She was so happy that she has cried/cried with joy.

cried 

300

we + to know

we knew

300

we + to know 

we have known

400

Today is Sunday. Adam has run/ran early this morning. 

has run 

400

you + to take 

you took

400

you + to take 

you have taken

500

She is now going to the zoo because she hasn't seen/did not see the elephants. 

hasn't seen

500

I + to win

I won

500

I + to win

I have won