Question: When to use Present form, when to use Base form in se

I think it depends on the perspective or how you say the word then the present and base form could be used.
for example:
Madalas akong(1st Person) manood ng sine dito.
Madalas siyang(2nd Person) nanonood ng sine rito.
Madalas silang(3rd Person) nanonood ng sine rito.

I'll just offer my foreign ear...in modern - informal - conversations...I hear conjugations mostly of the infinitive or the completed past. Continuing and Contemplated...much less frequently...usually for emphasis to my ear. AND...I hear roots for so many verbs without conjugations. Search TDC for root frequencies vs a reduplicated current or future form - eye opening for many verbs.Madalas akong manood ng sine dito.I hear as...I often "like/need" to watch movies PA -- in the infinitive...most frequently a command or a like/need.The textbook...meeeeh! Too old...too formal...and not conversational. No one is going to tell you the book is wrong. But it does not feature informal native conversations. If you speak perfecct textbook Tagalog, you will hear you sound like a book. You can search the TDC or another corpus for many examples of everyday conversations. AND...you will find EVEN MORE VARIATION. Art form...listen for the bias...and train your ear.DEEP TAGALOG na po! :D That's what makes TAGALOG more fun DIN na po! :DEnjoy!