syntax - An i-adjective immediately before 「ください」?

Does it make sense to have an i-adjective (in て-form) immediately before 「ください」?

For example, when asked to choose between hot and cold coffee, can I use 「温かくてください」, or must I turn it into nominal phrase (温かいのをください)?

Another example, is it fine to say 「優しくてください」, or must I insert a て-verb before ください (優しくしてください)?

Answer

In Japanese, you always need a main verb to complete a sentence. If you directly attach an i-adjective to an auxiliary ください via て, then you will not have a main verb anywhere. You need at least one main verb in between:

温かくしてください
優しくしてください

In sentences with i-adjectives or copula, it may not be obvious that you are using a verb, but underlyingly, you do have a verb. For example, the ordinary ending of an i-adjective is い:

寒い

This い includes a hidden verb ある, which is not obvious because the sequence くある is contracted to い. If you place something that interrupts the whole hidden sequence, thereby preventing the contraction, then you can see that there is indeed a hidden ある:

　部屋は暗いだけでなく、寒くもある。
× 部屋は暗いだけでなく、寒くもい。
× 部屋は暗いだけでなく、寒いも。

With nouns or na-adjectives, you may end a sentence with だ, but that is a contracted form of である, which includes the verb ある. Again, it may not be obvious that だ is the contracted form of である, but if you place something that interrupts the whole hidden sequence and prevents the contraction, you can see that there is indeed a hidden ある:

　彼は生徒でもある
× 彼は生徒もだ
× 彼は生徒だも