Dear Rejlan Givens, thanks to your explanation I have been able to edit my post again, and make my point clearer, I think

I invite you to check it out linguistics.stackexchange.com/questions/44127/phase-and-aspect

Po is far from being the only morpheme that is used to turn the atelic base verb into a telic one. There is a number of morphemes (prefixes) that serve the telicizing purpose, and a number of other ones for other sorts of verb aspects such as inchoative, iterative, temporary etc. Also, the same morpheme can be used to express different aspects - there is no one-to-one relation between the individual morphemes and the aspectual meanings

Can -po express another aspect meaning than telicity? If yes, is it really pervasive?

Here are some telicizing morphemes, off the top of my head: kuvati - skuvati (s), (cook - cook up (if we take "up" as an aspectual particle in English that can indicate completion of the event), graditi - sagraditi (sa) (build - build up), praviti - napraviti (na)(make - make up) , peglati - ispeglati (or opeglati) (is or o, two options) (iron - iron up) etc.

Yes, po can be used to express a sort of iterative aspect for example: Pokupovali su svo brašno i ulje. (kupovati - pokupovati (buy - buy over again), or inchoative aspect (verovati - poverovati (believe - start believing) and probably other aspectual meanings that might or might not be subsumed under these.

Ok, but potentially, it doen't seem false to say that -po is a telicity aspect marker

It is just that it can ALSO be a inchoative aspect marker and interative aspect marker

(I am not specialized on the linguistics about aspect at all, so I am not sure)

Telicity is not a verb aspect - it is a property of the situation. Verb aspect is about the way the situation unfolds in time or how you see that situation, and can be either lexical or viewpoint aspect. So the situation can be telic and inchoative, telic and iterative, telic and perfective, telic and imperfective etc. For example the situation of building a house is telic- it is about the semantics of the situation - there is a culmination point which is denoted by the verb's object

What is telicity if it is not a verb aspect? Because the telicity prefixes are attached to verbs, additionally verbs describe situations, and the prefixes give information on this situation.

There is a complicated relationship between the telicity and verb aspect, especially when you consider things cross linguistically. English verbs are neither telic nor atelic - the property of telicity is not in-built in the English verb - it is composite. By contrast, Serbian verbs are either telic or atelic - this property is part of the verb's semantics.

It sounds to me that, at least in Slavic languages, telicity is a verb aspect : "Jesti" is an atelic verb whose telic counterpart is "pojesti". It is the prefix -po that gives the verb its telic aspect

This fact affects aspectual representation of situations in myriad ways. For example, telicity of the verb blocks imperfective presentation of the situation. For example, you can't present a situation as ongoing if the verb tells you that the culmination point has been reached. If you have made something you can't in the same breath say that it is/was being made - you can't possibly take that viewpoint

Things are different with English verbs - nothing in the verb's semantics prevents you from presenting the situation as ongoing: you can eat something or be eating something, simply because there is nothing in the verb "eat" that prevents you from presenting the event as unfolding in time.

So, to answer your question, telicity is not a verb aspect - it is a property of either a verb (in Serbian) or a situation (in English).

"By contrast, Serbian verbs are either telic or atelic - this property is part of the verb's semantics." There are Serbian verbs that have a telic aspect WITHOUT having attached to same any prefix that specifically express telicity? If yes, is it pervasive?

Of course there are, telicity is derived from the interplay of the verb's semantics and the morphology of the language. The base form of the verb is atelic or telic to start with, and whether it is one or the other depends solely on its semantics. If you can't decompose the verb into the morpheme + the base, it means that the telicity will be changed through the attachment of the appropriate morpheme.

So but what is a verb aspect?

The verbs "kupiti" and "prodati" (buy and sell) are telic, and that comes from the semantics of these verbs. They imply the existence of a final state of a sort - you have something in possession or you got money for something you sold.

These verbs are morphologically simple (there are no identifiable morphemes attached to them or the base on which they are built on). Clearly, semantics of verbs can't be explained in such straighforward way, but it sure provides a starting point to think of the telicity and atelicity of verbs.

You need to read up on the verb aspect to get an idea of its purpose in language. There is a lexical aspect, which is concerned with the internal semantics of verbs (properties such as durative, stative, eventive, instantaneous etc.) and the viewpoint of aspect, which is concerned with the way you present the situation.

My suggestion is you get acquainted with the concepts of lexical and situation aspects.

In your terminology, verb aspect refers to grammatical aspect?

Perfectivity and imperfectivity, which I commented on in this thread, refer to the viewpoint aspects of the situation.

Sorry but I don't know what you mean by "verb aspect" so I can not agree with the statement "telicity is not a verb aspect".

It is okay, you are entitled to your opinion. I still suggest you get acquainted with the subject more before you choose to agree or disagree on the theoretical status of this concept.

Not agreeing or disagreeing on any "theoretical status of concept", only on what is being asserted without clarification of the terminology used.

I didn't use any terminology outside the generally accepted terminology in current linguistics. I don't see the point thinking of "telicity" as verb aspect, if that is not what the term "aspect" is generally used for in linguistics. Verb aspect is the term linguists use to refer either to the properties inherent to the verb (lexical aspect) or the perspective the speaker takes in referring to the situation (viewpoint aspect)

Telicity is neither of that, and in English it is not even a property of a verb, the more reason to avoid referring to it as "verb aspect"

"By contrast, Serbian verbs are either telic or atelic - this property is part of the verb's semantics.", "Verb aspect is the term linguists use to refer either to the properties inherent to the verb (lexical aspect)", "Telicity is neither of that (...) the more reason to avoid referring to it as "verb aspect""

"Telicity is not a verb aspect - it is a property of the situation.", "Verb aspect is about the way the situation unfolds in time"

Verb aspect is a complicated subject, I hope this discussion inspires you to further research this subject