/He opens his mouth/
/but the words won’t come out/
/He’s choking, how?/
You might have recognized the lyrics …. it’s an Eminem song… about a rapper unable to actually perform. Well this can happen to anyone, especially those speaking a second language.
The post of today is about the ”bottleneck hypothesis” a concept I read about sometime ago.
This bottleneck is what makes it difficult, it’s the reason why we know so much but talk so little.
I’ll try to sum it up for you not only because I find it interesting but mostly because it gives an insight on how learning a language works.
Let’s start from the basics.
How do we learn the meaning of words in English?
When learning a second language we need to learn the lexical items first.
We cannot speak a language without its words.
Learning words is relatively smooth but applying grammar, the endings for instance, is different.
What are the endings? Have you ever met -ing or -ed or -er or -st or just a simple -s at the end of a word?
Once a person learns that the -ed ending of the verb means past tense, the learner knows it as a rule, and they can apply it to all the regular verbs.
Although lexical items take time to learn and have to be memorized one by one and they seem the biggest problem, grammatical word endings are actually the hardest to learn.
They may be repeated in sentence after sentence, but they carry a lot of linguistic information.

This is where the ”bottleneck hypothesis” by Professor Roumyana Slabakova gets interesting, it can help explaining what is hard and what is easy in second language learning.
This picture illustrates the bottleneck hypothesis.
Imagine language as a bottle. The vocabulary you know it is contained inside and when you speak, all those words have to go through the bottle opening, the bottle neck, the narrow opening. This rapresents all those grammar structures that allow fluency.
When we speak our native language the words flow effortlessly.
When we try speaking English with the bits and pieces of rules that we have learned we see that words cannot come out as fast as they could. There is a bottleneck.
This concept illustrates that even if you have a lot of knowledge of the second language, the tight place through which it all comes pouring out are the little words and the word endings with grammatical meaning. We call these parts of words grammatical or functional morphemes. Without those morphemes, sentences do not work.
You may not learn all of this information at the same time. It may be coming one bit after another. But you need all of that information in order to be able to produce and to understand a good, acceptable English sentence.
This was adapted from https://www.futurelearn.com/info/courses/understanding-language/0/steps/4144