1) اشتريتُ بعض الخضروات لأحضَّر القليل من الحساء = I bought some vegetables to make some soup. Here I used "لِ" which means "to" and after it comes a verb. 2) اشتريتُ بعض الخضروات لتحضير القليل من الحساء = I bought some vegetables for making some soup. Here I used "لِ" as well which means "for" and after it comes a noun. 3) اشتريتُ بعض الخضروات من أجل تحضير القليل من الحساء Here I used "من أجل" which means "for" and after it comes a noun "تحضير". 4) اشتريتُ بعض الخضروات لِكَيْ أُحَضِّرَ القليل من الحساء Here I used "لِكَيْ" which means "to" or "in order to" and after it comes a verb. PS : you can use other verbs not only the verb "أحضِّر" Here some of them : Verb===========>Noun إعداد <=========== أُعِدّ I make=========>making طبخ<===========أطبُخ I cook=========> cooking طهو<=========== أطهو I cook==========> cooking PSS : As a last point I would like to tell you that you don't need to put "أنا" = "I" before the verb like you did "أنا أشتريت" but it's sufficient to say "اشتريت" which means "I bought" because the "I" is mentioned already. Look here down the explanation : "اشترى" = "to buy". "اشتريت" = "ت"+"اشترى" = "I bought". But it stills correct to say "أنا اشتريت" and as a recommendation from an Arabic native speaker don't mention the "I". Good luck)

You can use letter ل as a prefixes to mean to اشتريت بعض الخضروات لأعدَّاد/لتحضير شربة I advise you to look for these words كي/ من أجل/لأجل/لكي to mean for