A person has studied a foreign language. The person describes their daily routine in that language. They talk about past events. They discuss their hopes for the future, their fears.
The conversation turns to a favourite topic: food and drink. Sport follows. Film. Television. An art exhibition. The person describe symptoms and allergies.
They can even provide simple political arguments or state their religious beliefs (or lack of).
Fluent? Maybe. Maybe not.
The standard described above roughly corresponds to B1 of the Common Framework of Reference for Languages (CEFR). A good Higher GCSE. Able to cope alone in a region where the language is spoken. Potentially fluent but not quite.
For whatever reason, once a student has reached B1, they find the next step – B2 (can interact with a degree of fluency and spontaneity) – almost impossible.
The leap between B1 and B2 seems huge, compared to the transition from A2 to B1, and the student can often feel they are wasting their time.
I can hold conversations in French and German (in Past, Present and Future), but I regularly experience frustration at my limited vocabulary in both languages and my lack of mastery of abstract concepts. Basic Russian conversation continues to prove a challenge.
There are no easy answers to the problem of how to progress from B1, other than further practice and determination, along with a grudging respect for the humble B1 standard, which entails about 4,000 words, anyway.
A person stranded in a country where the language is spoken would certainly survive with 4,000 words. But further study is always good.
Just a few of my thoughts.