不能得到 vs 得不到 difference
I like to distinguish verbs of more than one character in two categories:

可分離 (You can separate the two parts and put a character in the middle)

不可分離 (Strictly forbidden to separate the two. They need to be together)

In the 可分離 category you will find:


動賓 (Verb + Object)
動詞 + 結果補語 (Verb + Result complement)


得到 is a verb with a 結果補語 (result complement).
For this kind of verb, the first character carry the main verb part. The second character is the result.
You can negate the result if the result is not achieved by adding 不. Or you can emphasize the success of the action or ask a question about whether it succeeded or not by adding 得.
Remember that this kind of verbs is special because you can always separate the two parts adding either "不" or "得" in the middle.

說出來 -&gt; 說不出來， 說得出來
吃下 -&gt; 吃不下，吃得下
撇清 -&gt; 撇得清，撇不清
聽懂 -&gt; 聽得懂，聽不懂
離開 -&gt; 離得開，離不開
記住 -&gt; 記得住，記不住


You can see that 到，出來，下，清，懂，開，住 are all results here.

得到 seems a bit special, because the verbal part is already "得". You can say 得不到，but 得得到 is strange!

我雖然努力學習，但好像還是得不到好成績


動賓 (Verb Object) is also interesting:

見面 -&gt; 見個面
吃飯 -&gt; 吃個飯


This time, you can separate them to add a measure word. And when you think about it, it makes sense: you can count the object part.

動賓 are special because the "object slot" after the verb is already busy. It means it's forbidden to add a second object immediately after.
「我想見面王先生」 is wrong.「面」already occupies the "object slot". So you can't add「王先生」since it's a second object.
Instead, you need to use another construction which separates the two objects:「 我想跟王先生見面」

我想吃飯麵糰 is also wrong for the same reason. Here, so as to make the "object slot" free for what you want, you can actually remove the「飯」part.
我想吃麵糰
This technique can also be used with 見面. You can make the "object slot" free by removing「面」. This will allow you to put your own object right after the verb.
我想見王先生

Think of the objects in the Verb Object category (面，飯) as a default object if you don't want to specify one. This allows the verb to still be a bigram so that it becomes a bit longer and easier to pronounce and to understand.

That explains why when we say 我想吃飯, it doesn't necessarily mean that we are going to eat rice. Rice was just the default object as we didn't specified our own. It only means "I want to eat."

「不是不是！我真的想要吃飯啊」

But it could also be that the object we want to select happens to be the default one! Then the sentence above could also mean "I want to eat rice".

不可分離 category

留學
參考
害怕
活該
住院
處理


You'll see that no matter what, the two characters need to be together for the verb to be complete. They can't be separated, because they are both part of the verb meaning. You can not put any 個，得 or 不 in the middle.