"Sometimes you see me."
Translation:Soms zie je mij.
The -t is dropped when the je/jij comes after the verb (inversion). That's just the rule. Only for the second person je/jij (not the polite form "u"). So you do say "Je ziet mij", "Soms ziet u mij" and "Soms ziet hij mij".
Because the second ‘position’ in the sentence is always occupied by the verb, which means that if the first position is occupied by a word or phrase that isn't the subject it displaces the subject to the first available position after the verb.
Notice that a position isn't strictly occupied by a word, but basically by a phrase, so the verb isn't always the second word but it is always in second position. For example let's take the sentence ‘je ziet een grote hond hier’ (‘you see a big dog’). If we move ‘hier’ to first position it will result in ‘hier zie je een grote hond’, but if I decide to move ‘hond’ we have to move everything that comes with it, so: ’een grote hond zie je hier’.