"Pasok" and "Trabaho" are both nouns and can be used as Subjects or Objects in a sentence. As nouns Trabaho exclusively means 'work/job' and Pasok can mean any activity that you go to on a regular basis with a schedule that will occupy your time... like school, training and even work. They are also verbs (in the base form) but in Tagalog you cannot use a verb in the base form like you can in English (unless you are talking in the imperative "Pasok!" as a verb would mean "Go In") So we must conjugate them to turn them into verbs. 

For Pasok (Present Tense/Present Progressive Tense) we add 'puma'= pumapasok

(Past) we take 'pu' add "ma" in the middle and then end with 'sok'= pumasok

(Future) we just add pa to the base form = papasok

Trabaho is a bit different

(Present/Present Progressive) prefix "nag" + tra + base form trabaho= nagtratrabaho

(Past) just add the prefix "nag"+ base form= nagtrabaho

Future = prefix "mag"(this denotes intention) +base form =magtratrabaho

Additionally these words can be adjectives too "Pasok!" can mean 'one that got in' and if you add "ma" to trabaho, it can mean tedious or something that requires too much work. =matrabaho