"اعطيني " works only for female for male you should say "اعطني" the (يـ) is always added at the end of the main verb letters for female order only (this the most common answer but if you are studying deeper in Arabic grammar "اعطيني" works for both but it's so uncommon and used only by so old natives

in Egyptian " متسبنيش " levantine arabic and standard " لا تتركني " but pronouncing differs

i see you new more about harakat down there i hope you understood them well if you need more i can help it's (shuk-ran) if you insist on breaking it but in arabic you shouldn't break words into syllables just follow letters and harkat and this will be easier by practice

in standard arabic when the work ends with (ا) we add this mark (اً) we call it tanween and it's equal in pronouncing to (ن) N letter added to the end of the word so marhaba becomes marhaban in standard arabic and by the way thanks is pronounced (shukran) not (shukian)