I am not a formally trained educator. I have minimal training for teaching reading to English-speaking adults who are illiterate and have had success with several students using a one-person-teaches-one-person basis (Lauterbach method).
However, I have now been assigned students whose native language is not English, but Spanish (which I do not speak or read). The first student, a man in his mid-30s with an 8th grade education, has been a wonder. From knowing a handful of English words, he now (after a year and a half) is an avid reader of American history, speaks in some areas better English than native speakers and is a delight, exploring idioms and sarcasm. I tutored his Aunt to successfully complete her citizenship requirements. The man's wife, though is a different matter. Either she is dumb as a post - I know, not politically correct, especially for a teacher! - or I don't have any idea how to approach this problem. I falsely began with instruction in reading English, which I have now abandoned. She can read English and mostly understands what she reads. But, in the five months I have been trying to get her to carry on a conversation, I am very frustrated. I pointed out to her that in nearly all instances, repeating nearly all the words in a question and adding the appropriate positive or negative words will be correct. Such as, "Do you like ice cream?" "Yes, i like ice cream." or "No, I do not like ice cream." If I write the questions down, she can write a nearly proper answer. It took me three weeks (three hour-long lessons a week) to get her to remember to wake her daughter with "Maria, it is time to get up." I think vocabulary is secondary to teaching how an English sentence is constructed. I am shortly to begin instructing 5 or 6 co-workers of hers in a group lesson and need help. None of these people will need to learn English to go to higher education; only enough for daily activities where they will interact with native English speakers. Any suggestions? The internet is very helpful, but I need a lesson plan. What to teach first, etc.
Have you taken any ESL training course? If a literacy council or your school system offers one, I'd highly recommend that.
In general, teaching ESL students involves lots and lots of repetition. While it's possible your student has some sort of memory problem, more than likely she simply needs more repetition and practice. It can be hard for learners to practice at home if their schedules are overloaded with work and family obligations, and if they are surrounded by Spanish speakers.
What text are you using? I like the Side by Side books, but I've found my Korean students, who can read English quite well, rely too much on that which impedes their improvement in speaking. It's my fault as a teacher and something I need to work on--I should not let them read when they do the repetition exercises.
With ESL students, I focus much more on vocabulary than sentence structure in the beginning. First they need to be able to get their point across; later they can perfect their grammar. That does not mean I don't correct their sentence structure, or that I don't mention it, but rather that it's not the focus. If a student says, "Maria, get up it time", I might reply, "That's close....Say "Maria, it's time to get up". You can break it down and have her repeat "Maria, it's time" and then, after you, "to get up".