My conlang uses verb conjugations only in the present tense. To indicate other tenses (preterite/past imperfect/subjunctive/future/etc) I use the combined phrase "sona," meaning "in (the) time (of)" and then adding a various suffix to indicate the specific tense("sonasato"="in time past"). This means I only have the present tense of conjugations per verb, not changing the actions of the subject per tense. (In English, you have "I eat" (present) and "I ate" (past), as one example. In my conlang, you use "In the time of past, I eat." (Past, but using a present conjugation.) What I'm wondering about are the places where I should put this simple tense indicator in a sentence. The conlang's sentence structure is like this (using an example from English as translation): English:
The dog drank from a bowl of water.
The dog(determiner+noun)-> drinks (conjugated verb, "it drinks") from (preposition) a bowl (determiner+noun) of (preposition) water (noun).
In my conlang, you would say
Sepyew ("(it) drinks", conjugated form of "to drink" in present tense) eu bítõe (the dog) de è roum (from a bowl, this would be contracted into "dè roum" or "dèroum.") de aqua (of water.)
This, however, was the present tense. The past tense (The dog drank from a bowl of water) involves the "sonasato"(in the past tense) in some form, but I don't know where the most logical place to place it would be. Ordinarily, that wouldn't present a problem.
Unfortunately, my conlang has no punctuation, that is to say, sentences are one long string of words. I've not considered how to handle this with dialogue, but otherwise it hasn't presented a problem until now. Pauses for breath within conversation are natural, but I'm addressing this question from the written aspect of language. Because the sentences are fluid, I don't know how to handle the abrupt changes between tenses other than using the "sona" variants excessively. And the rules of the language mean that the tense is always expressed, per statement (not sentence, because of the punctuation) by either ignoring the sona rule (indicating the present tense) or by using it (to indicate some other tense.)
Keeping that in mind, what would be the most logical place to place the tense indicator so that I can change it relatively easily between tenses in a language with no periods or commas (pauses), and where?