The Adjective form of a Verb - a special feature of Japanese
I just had another Japanese language epiphany. To express a feeling of desire with an action, the たい (tai) suffix tends to appear at end of a verb stem like 食べる (taberu, to eat). So 食べたい (tabetai) is "I want to eat." But, what I never considered is that, in this form, it becomes an い (i) adjective.
い-adjectives can be past or present tense in the negative or positive (in at least two or more levels of politeness). Casually, they can be:
～い
～くない (neg.)
～かった (past)
～くなかった (past neg.)
For example, "it was not delicious" could be 美味しくなかった (oishikunatta), from 美味しい (oishii), "delicious." With the い-suffix changing to くなたった to form the negative past tense. It "is not delicious" (present-tense) would be 美味しくない - by changing the い to くない.
If 食べたい is an い-adjective, then you can change the い to くない and say 食べたくない (or 食べたくじゃありません; tabetakunai or tabetaku ja arimasen), for "I do not want to eat." You can even say 食べたくなかったです (tabetakunakatta desu) for "I did not want to eat."
This is not intuitive in English because the adjective that modifies nouns or verbs is frequently a separate, adjacent word (e.g., "she is a quick runner," "he ran quickly"). And sometimes that's also the case in Japanese (for example, 彼は早く走ります / kare wa hayaku hashirimasu. "hayaku" 「早く」is an adverb for fast or quick, in this context, and hashiru 「走る」means to run ). However, a simple sentence like this in Japanese is often more consise.
Returning to this example (and others like it, such as 飲みたい / nomitai, "I want to drink"), it is possible to replace three English words with one or two Japanese words in: "I want to eat" = 「食べたい」or 「食べたいです」。On top of that, because of this verb becoming an い-adjective, one must think to replace five or six English words with one or two Japanese words in: "I did not want to eat" (or "I didn't want to eat") =「食べたくなかった」(or 「食べたくなかったです」more politely).
I find it's easier to merely understand what I'm reading or even hearing in Japanese than to translate it back into English because of having to find all of the extra words that reconstruct the original meaning.
English definitely Tries to shorten things up with contractions, portmanteaus, acronyms and even slang. But my feeling on that are that these terms (sometimes completely brand new and sometimes "made-up" sounding) are like hacks and work-arounds to try to speed up communicating in English. I'm sure that in my short amount of time of studying it, listening and trying to read it, I've missed subtle instances of Japanese having to be "mangled" by native speakers in order to better express a feeling. However, so far, my impression as a foreign learner of Japanese is that the language has many of these efficiencies "built-in" with the grammar it already comes with.