Past tense of a simple sentence

Yes, the conjugation is the same and context usually helps show past tense. There is also "na' that can be added to some sentences to show something is completed, which usually means past tense (but not always). For other times you can use "noon', "dati', or "kanina' or simply put the day/time it happened in the sentence.For your example, just adding "Dati' at the start would set the past. "Dati ang babae ay maganda." You could then add "pero ngayon hindi na" if you wanted. I'm not 100% sure But I think you could also put it at the end, " Maganda ang babae dati". But we can let a native speaker say for sure.Kanina works like dati but it is specifically for something that happened earlier within today. "Kaninang umaga' = earlier this morning

@calingaerta Filipino does not have the equivalent of the verb "to be" or "be", which takes the "am, is, are, was, were" meanings in English. The "ay" might look like it's that verb, but when the sentence is stated in the inverted order, the "ay" is removed and would, therefore, indicate that it does not function as the "to be" verb. It just serves to link the subject to the predicate in the subject-predicate form of a sentence."Ang babae AY maganda" = "Maganda ang babae" = The woman is beautifulEven if we can consider it as the "to be" verb in a sentence, there is only one form of "ay" and it will always translate to the present tense if there is nothing there that can contextually indicate that the sentence is in a different tense.Daoxin's answer is correct. When "to be" is the only verb in a sentence, then we need to use a time indicator/marker or a contextual cue to indicate past or future reference.For the distant past, "noon" (then) and "dati" (before, formerly) are used to generally refer to that time. A more specific period in time may also be used for that purpose."Ang babae ay maganda noon/dati" = The woman was beautiful then/before. - This English translation is not precise though because it would more likely be interpreted as "Women were beautiful then/before". It would be better to state this sentence by making reference to a specific woman instead. "Ang babaeng iyan/iyon ay maganda noon/dati" = That woman/That woman yonder was beautiful then/before. "Ang babaeng iyan ay maganda noong nasa college pa siya" = That woman was beautiful when she was still in college."Ang babaeng iyon ay maganda nang nakita ko siya noong Pasko" = That woman (yonder) was beautiful when I saw her last Christmas.As Daoxin also mentioned, you may add "pero ngayon hindi na" (but not anymore now), although that would not really be necessary as it would normally be already understood."Ang babaeng iyan ay maganda siguro para sa magiging asawa niya balang-araw" = That woman would maybe be beautiful to the one who'll become her husband someday.

@Daoxin Yes, you may place "dati" at the start or at the end of that sentence. However, again, it would make better sense if you make the "babae" specific."Dati maganda ang babaeng iyan" and "Maganda ang babaeng iyan dati" are both correct.You may also just use "ang babae" if it will be understood contextually that you are referring to a specific woman. For example, let's say that there is this male and female pair that we regularly see dancing on TV. Then one day, the man has a different female partner. It would be correct to say, "Maganda ang babae dati" or "Dati maganda ang babae" because that would refer to the female dancer and the statement will be understood to mean that the new dancer is not pretty at all.

When I was typing the answer I thought specifying that woman sounded better, but I just wanted to stick to OP's example for simplicity.

@Daoxin It will usually be correct when used in the present tense because as "Maganda ang babae" is being said, most likely the woman being referred to is within view and therefore, specific. However, in the past and future tenses, they need to be specified for clarity.

@Tagamanila @Daoxin Maraming salamat para sa inyong kaalaman! I kind of figured that it would be context (adding something to create context) as the to be/is/are isn't explicitly laid out in Tagalog. I really appreciate the in depth explanation and even answering what I didn't ask like creating a sentence that describes the future!I'm pretty sure I understand from a previous post that "Magandang babae" = "beautiful woman" and "Maganda ang babae" = "the beautiful woman" although I imagine it would be hard to distinguish the difference myself if a native speaker is talking. Would this distinction be important when using something like iyan and dati? As in "Magandang babae iyan dati" not making sense vs "Maganda ang babae iyan dati". The difference seems almost nonexistent but it seems like some of these small differences can influence if things sound right on the ears or just seem a little off.Also all the examples you presented have a "Ang babeng iyan ay ..." format. Was this done just to show it in a closer to English form to help me understand or would a native speaker say a sentence this way? My initial guess would be a speaker would say "Maganda ang babeng iyon nang nakita ko siya noong Pasko" instead?

@calingaerta "Magandang babae = beautiful woman" is correct. "Maganda ang babae" is not "the beautiful woman". It is "The woman is beautiful". In "magandang babae", "maganda" is an adjective modifier of "babae". In "maganda ang babae", "maganda" is an independent adjective that is part of the sentence's predicate.

@calingaerta "Magandang babae iyan dati" is grammatically correct and it makes sense - That (woman) was a beautiful woman before."Maganda ang babae iyan dati" is not correct. It should be, "Maganda ang babaeNG iyan dati"."Maganda ang babaeNG iyan dati" = "Maganda ang babae NA iyan dati" = "Ang babae NA iyan/Ang babaeNG iyan AY maganda dati" = That woman was beautiful before.

@calingaerta Yes, I often use the "ay" forms to show how the placement of the words correspond to their English translations. Since we now usually start a sentence with the verb or the predicate, "Maganda ang babaeng iyon nang nakita ko siya noong Pasko" is how you would most likely hear it instead of "Ang babaeng iyon ay maganda nang...".