This construction is pretty straight forward. One thing to remember is that this is the "since" that is related to "because" and not the "since" that is used with time expressions (e.g. "I have been living in Indiana since 2018"). Most likely you will hear عشان used to express 'since' more frequently than بما إن.
Example 1
معلش اخر حاجة. بما إننا لوحدينا يعني ومفيش حد سامعنا..... بس كنت عايز أعمل مكالمة من تليفونك لامي |
| Sorry, last thing. Since we are alone and nobody is listening...I just wanted to make a call from your phone to my mom.
(لا تراجع ولا استسلام) |
Example 2
طب بما إني اتكلمت كتير يعني انت ممكن تتكلم شوية |
| Since I've talked a lot, you can talk for a bit.
(فوق مستوى الشبوهات) |
Example 3
بما إننا زملاء في وزارة واحدة أنا قلت لازم أنصحك |
| Given that we are colleagues at the same ministry, I said to myself that I need to give you advice.
(جواز بقرار جمهوري) |
Example 4
طيب بما انك بقى عايز تقعد في البيت تعالى عشان عايزاك |
| Well, since you want to stay home, come here I need you (for something).
(اهواك) |
Example 5
واجب عليك انك تشكرني اه يعني بما اني هخلصك من وجع الدماغ ده |
| You should thank me, you know, since I will save you from this headache.
(الدالي) |
Example 6
بما ان الكبير اكده اكده نازل الكفر يبقى لازم تقعد معاه وتخلص الموضوع ده |
| Since the Kabeer is already going down to al-Kafr, you need sit with him and finish this issue.
(الاب الروحي) |
Example 7
أنا مُتفهم لظروفك لكن البنك من حقه يتصرف لحماية مصالحه بما إنك ممتنع عن السداد |
| I have been explained your circumstances but the bank has the right to act to protect its interests given that you refuse to repay.
(بشتري راجل) |
Example 8
بما ان دي اخر مرة هتكلم فيها معاكي انا هحكي لك القصة اللي خلتني اقرر اعيش لوحدي في الدنيا |
| Since this is the last time I will talk with you, I will tell you the story which caused me to decide to live alone in the world.
(بنتين من مصر) |