When spoken with the correct accent, the words "tawagan" and "tawagin" mentioned by "neealio" refer to five words with different meanings, not just two. This particularly important matter concerning proper accentuation of spoken words had seemingly been abandoned by the Philippine education authorities since a long time ago already. I myself am not very sure about the proper stress mark to use and where to place it, but I will say anyway what I have in mind. I will just hope that somebody more knowledgeable than me would give the necessary corrections. For "tawagan", we have the accented words:
(1) "tawágan" (the letter “a” acute in the second syllable, with a sudden onset of a brief rise in the voice), which is a verb in the imperative mood commanding someone to call somebody by using a telephone or any communication devise (as in “Call up father in the office” or “Tawágan mo si tatay sa opisina”), and
(2) "tawagàn" (the letter “a” grave in the third and last syllable, with a slight drop in pitch), which could either be a noun, a word in the indicative mood, (as in "Tawagàn ng mga tao ang telepono” meaning “People communicate with each other by using the telephone” or “Ang tawagàn nila ay giliw at mahal” meaning “ ‘Darling’ and ‘love’ are the names they call one another”, in referring to a married couple), as well as another verb in the imperative mood (as in "Tawagàn nalang tayo”, or since the word "magtawagàn” can be contracted to "tawagàn", one could also say "Magtawagàn nalang tayo” meaning “Let’s just call up each other”).
We have just seen above how the single word "tawagan" without any stress mark could have three different meanings.
With regards to the unaccented word "tawagin", we likewise have the two accented words:
(3) "tawágin" (the letter “a” acute in the second syllable) is a verb in the imperative mood so that a person of authority could say, for example, "Tawágin si Pedro” (“Call Pedro”) if Pedro is not within a hearing distance so that shouting out his name would be futile, and no other means were available to contact him except by fetching and bringing him in to finally enable the person of authority to talk personally to Pedro;
(4) "tawagìn" (the letter “i” grave in the third and last syllable with a slight drop in pitch) that denotes an adjective, as in "Tawagìn si Pedro sa pangngalang “Pedrong tinting’ dahil masyadong payat siya", indicating how often Pedro is being called by a certain name, and which translates into English as something like “Pedro tends to be called ‘Pedrong tinting’ because he is very thin”. “Walis tinting”, by the way, is the Tagalog term for broom stick.
That is how the two written words "tawagan" and "tawagin", both without stress marks, could have five different meanings.
