Hello all. I have been a long time lurker on these boards and decided to register I have so many questions of my own. I am currently studying Arabic at university and I am in my second year. Due to studying another subject alongside Arabic, it isn't as good as it should be. Anyway, I am having difficultly in understanding the fourth verb form أفعل. For example, if I had the verb كمل, it means 'he completed'. By adding تُ to the end, it becomes 'I completed'. My prefixing an أ to the root letters, one gets أكمل. This is where I start to get a bit lost. What is the difference between saying أكمل and كملتُ or even ُأكملت?