“Ben de merak ettim şimdi,umarım okuldadır da,siz görememişsinizdir”. I seem to be able to understand the ending -miştim/-müştüm; with ‘me’ this is a negative form, but what about the suffix -dir? I’m a bit clueless 
I wanted to say from my memory that the suffix “-dır” adds the aspect of certainty to the verb, but now I’ve looked that up in “Türkische Grammatik für Anfänger und Fortgeschrittene” by M. Ersen-Rasch (which I can whole-heartedly recommend to you as a comprehensive grammar - and it’s in German, so you’ll benefit more from it than I do) and I’m not that sure anymore… I found it in sentences like “İnşallah sular da akıyordur”, so it cannot be certainty if it’s after “inşallah”, can it?
OK, you’ll understand it better than me:
“Das Türkische kennt ein Hilfsverbsuffix -dir, mit dem der Sprecher seine Überzeugung zu einem Thema nachhaltig einbringen kann. (…) Wenn es in der gesprochene Sprache vorkommt, bleibt die deutsche Übersetzung eines Satzes mit oder ohne “-dir” oft gleich (…). Die Überzeugung des Sprechers kann interpretiert werden als Bestätigung seines Wissens, oder sie kann zwischen Wissen und Einschätzung schwanken. Wenn die Überzeugung zwischen Wissen und Einschätzung schwankt, kann es kontextabhängig notwendig werden, im Deutschen ein passendes Wort hinzuzufügen, das dieses ebenfalls signalisiert (…)” The examples for German words are “sicher”, “eben” und “doch”.
okuldadır-görememişsinizdir.
görmek
görebilmek ability
görememek negative
görememişsin = It seems that you could not see (inferential/This tense is used where doubt or hearsay is in the speaker’s mind. It is often used in jokes and story telling as a reportative form.)
görememişsindir
-dır/dir It provides to word -presumably- here.
different alternative for this sentence
İnşallah siz görememişsinizdir de,o aslında okuldadır.
-dır suffix
suçlu-dur (s)he is guilty
kötü-dür (s)he/it is bad
yasak-tır it is forbidden
garip-tir (s)he/it is strange
customic is right " I wanted to say from my memory that the suffix “-dır” adds the aspect of certainty to the verb"
it also includes determination/statement
öyledir/yapmıştır/kitaptır/yüksektir/açıklanmıştır
certanity;
-Ooo, o çoktan gitmiştir.
-Treni kaçırdık,çoktan hareket etmiştir.
There are three basic,different type of -mış/miş
1—Copula ‘to be’. Inferential/Indirective
hasta-ymış (s)he is/was apparently ill
evli-ymiş (s)he is/was apparently married
yolcu-ymuş (s)he is/was apparently a traveller
2-- Past in -mış/miş
bil-miş (s)he/it has apparently known/knew
bul-muş (s)he/it has apparently found/found
3-Participle in -mış/-miş
bil-miş who knew/has known
bul-muş who found/has found
Thanks a lot, Piotr and Ozne. Your explanations make it a bit clearer. BTW I have had the above-mentioned Turkish grammar book for some time, but have not studied it systematically, just looking up what I could find. Often I cannot see the forest for the trees (and Turkish forest is a large one) - as we say in German too: den Wald vor lauter Bäumen nicht sehen können
I also possess this thick German-based grammar of Turkish, but for me it was overwhelming. So I rarely worked with it. Very useful for my Turkish grammar studies is/was the grammar of PONS “Grammatik kurz & bündig Türkisch”. This grammar has 111 pages and the writing is coloured in black and blue ( I like visual features!).
Fasulye
Thanks Fasulye for your recommendation. Maybe it would be useful to have a look at this “kurz und bündig” grammar of Turkish, but on the other hand there are probably only the most basic things in there, right? I had a short book for Turkish once, but it was not worth much and I gladly gave it away. I prefer to have a lot of examples and all grammatical features of a given language described, so that I can be sure I’ll find there whatever I’m looking for - it’s just what reference grammar is about.
-dir suffix in this sentence ‘‘görememişsinizdir’’ makes the sentences the meaning ‘‘maybe’’…maybe you couldn’t see