What effect can being unable to read well have on a grown - ups life

Adults probably wouldn't be able to get a job if they wouldn't be able to read. If you can't read then you can't learn. A lot of jobs depend on reading.

If an adult is unable to read well, he/she may have a hard time getting employed depending on the job they're applying for. They could also have trouble learning new things from books as that requires you to read and interpret information through words. Moreover, they could be seen as less intelligent by peers or co-workers.