It's difficult to explain beacuse the meaning of it depents on the situation
When you us it as a verb, it will be translate as "give" that pronounce "gei" like "I give you something" or "you give me something" that means 我给你一些东西 or 你给我一些东西.
We also use it to represent a passive situation e.g."我把机器给弄坏了" means " The machine is destroyed by me" machine is 机器 "is verb+ed" means 给.
Also it sometimes used before some verbs, giving stress to the tone e.g. 给忘了, 忘 means forget and 给 just stress 忘 itself