It could indicate the n noun class singular or the m/mi noun class plural. It could also indicate that the noun class is unknown, since n class is used for unknown objects or a collection of objects in different noun classes.
I think they can't press for only one prefix and - inaingia also is working.
The verb form generally consists of a subject-tense marker-verb (other infixes are also possible for objects and relatives, but those will come in later sections). In this case, subject = li (it, for a noun in the ji/ma noun class), tense marker = na (meaning present tense), verb = ingia (to enter).
So, the "li" in "linaingia" tells you the noun class of the subject that it is referring to in this context.
Thanks. That helps a little. Somehow this section deserves a big paragraph of grammar explanation. Here in the course I guess is the spot where people with zero Swahili foreknowledge will drop out otherwise...
yeah, it worries me that people need to read so many comment threads to find the answers that they're looking for. i'm hoping that as they develop the course, they'll provide better explanations of the grammar at the outset.
It is not the way duo works. To get more grammar, I strongly recommend you to find a complementary way to study. There are many good suahili classes in YouTube, and you can find good grammar tips in Wikicionary too. That are my favorite material, but you can find yours.
So do I. Until here it was fine. But suddenly there seems to be a crack...