Many parents ask how they can best help their students with homework. I understand how helpless a parent may feel trying to explain a math concept, science concept or even how to assist in an accounting assignment.
First off, you must help the student organize their time AND have an idea of what they are actually doing during that time. They can tell you they were working, but if you haven't dropped in on them or engaged them during the process, you will never really know.
But after that it's HOW you ENGAGE them that matters, not your content knowledge.
I, personally, didn't know some of the math terminology my son was working on last year and had to take a pause.
So instead of having the answer, which really isn't an ideal thing to provide, I had to evaluate the problem and work with him to figure out what was needed. After some frustration, he worked through the issue, with my help (mainly cheerleading and encouraging) and then was able to answer the questions.
This is why, at all levels, we need to de-emphasize getting the right answer. It's the process.
So, at home when you're asked how to help define a themes for a student in English, or which verb tense is needed in Spanish, ASK your students questions about what they're doing in class, what the teacher said, what is available online. Help them think through the process and come up with answers AND questions for the teacher.
Teacher's can answer specific questions about material and problems generated from student's attempting to solve problems. "I don't understand it," means the student hasn't tried to solve it themselves.