How is it convenient to store tasks for learning a foreign language in an Android application in a relational database?

Question

Android

It is necessary to design a mobile application for learning English on Android.

I plan to use tasks in the application at least similar to those in the Duolingo application:
1. translate words and sentences from Russian into English or vice versa
1.1. with closed full answers
1.2. with an open answer (entered from the keyboard)
1.3. with a closed composite response composed of a set of draggable elements. Only a certain set, assembled in a certain order, is the correct answer. There may be more elements than necessary, i.e. there are extra answers.
2. translation of the audio recording from English into Russian
2.1., 2.2., 2.3 are similar, respectively, to subparagraphs of paragraph "1"
3. pronunciation
3.1. Pronunciation of written English words or sentences aloud
3.2. Pronunciation of the translation of written English words or sentences into Russian aloud
4. there will probably be tasks with the selection of the correct answers to questions and questions to the answer, but I still do not know how they can be designed.

And pictures may also come in handy, and it is very likely that for 1 task there will be not one picture, but several, and the pictures will be tied to the answers. associations make it easier for a person to remember words than simple text.

How can all this be stored in a relational database?
I haven't programmed Android apps yet, so no particular DBMS is chosen.
It is planned that the application will work even without an Internet connection, that is, tasks can be downloaded and stored in a local database duplicate that is already on the user's device. However, receiving the tasks themselves requires an Internet connection.

I thought about how you can store words and their dictionaries on certain topics in the same database, and made a sketch for this in Excel. It is planned that dictionaries can also be downloaded to the device, as well as deleted.
Fk = foreign key, colors indicate which column the key refers to

Example of tasks in Duolingo (it lacks images):