help with Arabic present tense, please???

Question

how m I suppose to know when to put a wowel (A,e,I) in the stem?
such as in rasama-> arsUmu
in kataba-> aktUbu
daraba-> adr I bu
etc.
I m really stuck with this and I have a test in 2 days.
mn fadlek!

I figuredout I need 3. pers. sing. (male) such as yaktubu for kataba in order to make the present tense by removing suffix -u and prefix -ya

so what is that form (yaktaba) called exactly?? I thought its present participle, but apperantly not...

Answer 1

Well,as a native speaker studying Linguistics&Phonetics of Arabic &English language I would tell you that (yaktaba) is non sense word!
it should be (kataba) &it's the past tense you have to remove the present tense prefix which is(ya) -in this case- and add the vowels /a/ as an infix and suffix to give THE PAST not particible.
About adding the vowels,it depends on the tense &on how many letters that the stem is made of ?.
For example if we are making the past tense from a stem of 3 letters:
we put an infix after the first letter /a/ and another suffix at the end/a/.
in case of PRESENT we add a prefix either(a,na,ya,ta)
/a /for "myself" ,/na/ for plural, / ya / for a M ,/ta/ for a F.
and basicly a final /u/
Hope it helps.

*a part of my major is teaching Arabic as a foreign language,so if you have any questions ,don't hesitate to contact me.
have a nice day &good luck with your exam

Answer 2

My understanding is that you simply have to learn WHICH characteristic vowel is used in the perfect (katabu) and imperfect (e.g., yarsumu) forms when you learn the specific verb. But maybe the following will also be of some help.

http://arabic.speak7.com/arabic_verbs.htm

http://en.allexperts.com/q/Arabic-1635/root-Stems.htm
http://acon.baykal.be/