"That machine is a motor."
Translation:Tiu maŝino estas motoro.
Grammatically, isn't maŝino a female maŝo? Do a lot of words end in what looks like a suffix? Does it cause confusion, or is it the source of puns?
Yes, you could interpret it as a female mesh.
A fair number of words end in what looks like a suffix, yes, e.g. kolego (colleague) looks like kol'eg'o (long neck), and re'vid'o (seeing-again) looks like rev'id'o (dream-child), and aĉet'i (to buy) looks like aĉ'et'i (to be a little bit bad), putin'o (a whore) looks like put'in'o (a female well), and so on.
There are even words that were borrowed wholesale from other languages which look as if they end in a suffix but do not, according to Esperanto rules; some people have attempted to make pseudo-suffixes out of them (for example, a pseudo-suffix *AB from "lavabo", as if it had been formed from lav- + -ab- + -o rather than being a single root lavab- + -o).
In general, I think there is little confusion.
It is an occasional source of puns. ("Kiam ĝirafo neniam estas sola? - Ĉar ĝi ĉiam havas kolegon!")
Very important, just like keeping "s" and "c" apart. They can change the meaning completely.
For example, "ŝelo" = shell, bark, peel; "ĉelo" = cell.