For people who go traveling and aren’t fluent in the local tongue, it’s obviously helpful to at least be able to use the verb “to speak,” as in “I don’t speak [your language].” or “Does anybody here speak English?” I’m here to help you out, in Turkish, in Persian here, and in Arabic here.
The verb “to speak” is going to be konuşmak. There are other verbs that have similar meanings (to talk, to converse, etc.), but for the physical act of speaking this is what we’re going with.
The two key sentences are “I don’t speak Turkish” and “Do you speak English?” so that’s what we’ll look at. There are a couple of ways to say these. In the first sentence you’ll see the first person, singular, negative form of the present tense verb, and in the second you’ll see the second person, plural (formal) form of the verb in a yes/no question.
(Ben) Türkçe konuşmuyorum means “I do not speak Turkish.” Unlike Arabic and Persian, where you would probably not say “I do not know” in place of “I do not speak,” in Turkish you might very well say (Ben) Türkçe bilmiyorum or “I do not know Turkish” (bilmek = “to know). The particle -mI- inserted between the verb stem and the progressive marker (-yor) negates the verb. Ben is just the first person, singular pronoun. You may elect to leave it out, since the verb also conveys the first person, singular nature of the subject.
“Do you speak English?” is İngilizce konuşuyor musunuz? When asking a yes/no question in Turkish, you split the person/number marker away from the verb and stick it onto this mI (depending on voweling, it could be mi, mı, mu, or mü) marker, which is not translated but simply announces that this is a yes/no question. This question takes the second person plural –sunuz, because this is more formal (presumably, if you’re asking someone if they speak English, you’re not on familiar terms with them). “Do you know English?” is İngilizce biliyor musunuz?
There is another way to say this, which introduces the potential marker into the verb to convey the idea “can you?” To do this, you take bilmek and reduce it to its stem (bil), insert that (with a vowel in front, a- or e-, if needed) after the stem of the verb you’re using, then tack on the aorist (we’ll see this later, but for now think of it as simple present tense as opposed to progressive present, “is” rather than “is doing”) ending, which is –Ir. This is introducing a lot of new grammar, so don’t think too hard about that and just focus on “Can you speak English?” which is İngilizce konuşabilir misiniz?