Most of the time they get it right

At least, most of them do. Occasionally, though, my English learners make mistakes with the usage of most versus most of.

     "Most of students enjoyed watching The Life of Pi," someone said.

     I corrected her, explaining that you have to say either "Most students enjoyed the movie," or "Most of the students in the class enjoyed it." If you use most of, you must add the, and then use a modifying phrase or clause to indicate which specific ones from the general category (the plural noun).

Most of those who struggle with it eventually learn English, a vast, sprawling and somewhat lawless tongue, though there are some rules and patterns.

For most learners, language learning progresses in stages. First the learner is delighted to be able to communicate -- to speak and understand some words, sentences, and ideas in the new language.

When this ability becomes a relaxed routine, learning may plateau before the next stage is reached. Next, students of a new language start to pay attention to words and sentences before uttering them. They become aware of their errors, and are able to go back and correct most of them.

More calendar time passes, and learners keep practicing. Once they achieve a high level of fluency, they enter the next stage, in which they develop and perfect the ability to interrupt the mistakes before they utter or write incorrect forms.

Most students are also able, at this stage, to benefit from reflective correction -- when the teacher or other speakers reflects back their mistakes simply by using the expression correctly when responding to what has been said. (If reflective correction is tried too early, it doesn't work; language learners simply don't notice it, as they are busy struggling with other challenges.)

While they are perfecting the grammar, idiom and vocabulary, students may find that long periods of speaking and listening in English are still somewhat tiring; A conversation in English still demands much more mental effort than in does in the native tongue.

The final stage of language learning is mastery. Those who achieve this level are comfortable and spontaneous in the new language.  

Many of the students who tackle English never achieve complete mastery, but that's okay. They achieve enough fluency to get on with their lives. They make the most of (use to full advantage) the English they do know. Most of the time (usually), it is enough