And they say different things about you:
Type 1. You could not be bothered to invest the extra time to weed out obvious mistakes (and I am sometimes actually guilty of this on this blog, when jot down a quick idea).
- Small typos with a red underlining from the spell checker
- Obvious grammar mistakes resulting from incorrectly rewriting a sentence.
Type 2. Mistakes which you did not catch because you did not detect them yourself.
- Picking the wrong word in the wrong context (words that sound the same but mean something different)
- Less obvious errors in grammar.
When an investor reads your investor deck, she will probably forgive you, depending on the context. Sloppy "type 1" errors are OK in small informal notes, but leaves her wondering whether you would have the drive to weed out any source possible reason to lose a pitch in high-stake, all or nothing, efforts. I see many type 2 errors in documents by entrepreneurs who are non-native English speakers, and here it might trigger the "ultimately we need to get a US CEO" knee jerk reaction, as she is worried that you are not "presentable" enough to represent the company to potential big clients and/or future investors.
Better have that "all or nothing" deck checked by a native speaker.