değişmek - to change (intransitive);
değiştirmek - to change (transitive)
durmak - to stop (intransitive);
durdurmak - to stop (transitive)
Are there many verbs which go from intransitive to transitive by adding an extra dur, tir, etc. to the verb stem?
Yes...in fact, that suffix (-*DIr) is the causative suffix and can be applied to most verbs to give the meaning "to cause to..."
So someone going up into clouds and ‘seeding’ them to make it rain would be ‘yağmuru yağdırmak’?
Is there any reason why 'Benim telefonumu sık sık değiştiririm' shouldn't be accepted? Is it a missing alternative, is the 'benim' unnatural here, or is my word order a bit funky? Many thanks.
We had just forgotten to include translations with "benim." You will find that Turks tend to not use these unless they absolutely have to :)
Sıkça telefonumu değiştiririm, was accepted too.
I wrote "sık sık benim CEP telefonumu değiştiririm"
Is it wrong to have CEP in there?
"I change my phone frequently."
Translation: Ben sık sık telefonumu değiştiririm.
Doubled adjectives "sık sık" function as adverbs only & no longer function as adjectives.