Past Simple Present Perfect
+ zin : I walkED/ wrote (2e rij) + zin : I have walkED
he has written (3e rij)
- zin : I didn't walk (HELE ww) - zin : I haven't walkED
he didn't write (HELE ww) he hasn't written
? zin : did I walk ? (HELE ww) ? zin : have I walkED
did he write (HELE ww) has he written ?