Pretérito Regular
Pretérito Irregular
Imperfecto Regular
Imperfecto Irregular
Verbos Cambio Radical
100

My friends visited (as in they visited their grandparents on Sunday)

Mis amigos visitaron

100

We went (ir)

Nosotros fuimos

100

My friends visited (as in they visited their grandparents each week. 

Mis amigos visitaban

100

His friends used to go (as in to the store together). 

Sus amigos iban. 

100

Mark serves (servir)

Mark sirve

200

He lived (as in his lived in Spain for one year)

El vivió

200

They did (as in their homework) 

Ellos hicieron

200
He lived (as in when he was a child, he lived with his parents) 

El vivía

200

I saw (ver - as in my grandparents every week) 

Yo veía

200

I served (servir)

Yo serví

300

They swam (as in they swam at the beach on Sunday)

Ellos nadaron

300

He ate (the cake)

él comió

300

They swam (as in, they swam in the river each weekend)

Ellos nadaban

300

We were (ser - as in students at that school for many years)

Eramos

300

We get dressed (vestirse)

Nos vestimos

400

We ate (as in we ate too much for lunch)

Nosotros comimos

400

They told (decir- as in their parents about the problem)

Ellos dijeron

400

John felt badly (sentirse - as in after  eating too much) 

John se sentía mal

400

They were (ser- as in very serious)

Ellos eran

400

They say (decir)

Ellos dicen

500

The president spoke (as in for one hour) 

El president habló

500

Mary put (poner - as in the food on the table) 

Mary puso

500

We didn't know each other (conocerse - as in when we were children) 

No nos conocíamos

500

You were (ser - as in very intelligent when you were a child)

Tú eras

500

She slept (dormir)

Ella durmió