To describe a habit that took place in the past, the construction كَانَ + verb in the present tense is used.
كُنْتُ أَلْعَبُ كُرَةَ السَّلَّةِ كُلَّ يَوْمٍ
I used to play basketball every day.
When there is a construction of كان + present tense in the main sentence and regular past tense in the subordinate sentence, this construction takes on a progressive meaning.
كُنْتُ أَمْشِي فِي الطَّرِيقِ حِينَ رَأْيْتُ صَدِيقِي
I was walking down the street when I saw my friend.
You can use the verb صَارَ + present tense meaning "to begin" and refering to the present.
صِرْتُ أَعْرِفُ شَوَارِعَ القَاهِرَةِ جَيِّداً
Now I know (get to know) the streets of Cairo well.
