I'm pretty sure that level of nitpicking is outside the scope of what the the (non-native English speaking) poster meant when they said 'their english is terrible'.
Appreciating that you're undoubtedly communicating better in English than I would in your native language, the fact is that if you're a (principally) English-speaking company, with (principally) English-speaking customers, hiring (principally) non-English-speaking support or contract services, there will be communications issues, and those lead directly to business issues.
I've encountered this in dealings with companies, as well as within companies (one, otherwise brilliant, co-worker had the specifically annoying verbal tic of pronouncing the letter 'R' as 'A', which given local acronym naming schemes was very frequently encountered.
I've also, of course, met (and worked with) foreigners of all stripes with flawless (and often charmingly accented) English.
And that is my point. You can not hire people who do not have a minimum level of english. It is not the person's fault, but IBM's fault for hiring them.
> their level of english is terrible
Indians'/Chinese'