Why can't 連体形 verbs be in the past tense?

Question

While reading IMABI's entry on まで, I saw the following table:

Here the 連体形, or the attributive form of a Japanese verb, is characterized as being "non-past". This resource states:

In general the 連体形 is the name of the form of a noun or adjective used to modify or classify the noun. For example, when using こと or もの after an adjective or verb, the form of the adjective or verb is called 連体形. In practice, the standard 連体形 form of verbs and adjectives is the dictionary form. However, alternatives exist, such as the archaic き form of adjectives.

Question: Can't the attributive form be in the past tense? E.g. what's the problem with

喋った猫

which seems to mean

The cat that talked

Here is "喋った" not in 連体形 form?

Answer 1

It's strange to ask if 連体形 can be in the past tense, but a so-called past form (ta-form) can safely be in 連体形. た is a Japanese auxiliary (助動詞) that conjugates like this. In 喋った猫 ("the cat that talked"), 喋った is indeed the 連体形 of 喋った. The predicative form (終止形, aka dictionary form) and the attributive form (連体形) of 喋った look the same.

_{(As that article says, this is different in classical Japanese. The auxiliary for past tense in classical Japanese is き, but its 連体形 is し. See this chart. So 猫喋りき is "The cat talked", and 喋りし猫 is "the cat that talked". Here, き and し are two different forms of the same word, き.)}

What that table is saying is that ～まで (and ～前に) doesn't take the past form of a verb, even in the 連体形. This is because Japanese is based on relative tense. For example, "I waited until he came" is not 彼が来たまで待った but 彼が来るまで待った in Japanese. You can never say 来たまで even if everything in the sentence happened long ago.

For details, please read the following discussions:

• How to appropriately pair tenses in subordinate and main clauses?

  This entire concept is also why 後で always takes the past and 前に always takes the non-past. With 後で, the relative clause is always in the main clause's past (happened before it), and thus must take the past:

• Why 広がる前 isn't 広がった前 in this sentence