Avoid subject-verb disagreement when speaking. When using a singular subject, you should use a singular verb, and when using a plural subject, a plural verb. Therefore, you should avoid saying things like “He don’t” or “She don’t.” Instead say, “He doesn’t” or “She doesn’t.”
You should also avoid inadvertently choosing verbs that disagree with their subjects when you use expletive expressions to begin sentences. These expressions include “there is,” “there are,” here is” and “here are;” and although they begin sentences, they are pointing to or introducing the subject, which follows the verb, and are not subjects themselves (Barnwell & Dees, 1999).
The problem of subject-verb disagreement usually occurs when people turn these expressions into contractions: there’s, there’re, here’s and here’re. For example, someone might say, “There’s many people who don’t understand my position,” when he should say, “There’re many people,” because the subject of the sentence is “people,” not “there.”
Eliminate double negatives from your speech. Although it is considered acceptable to use two negatives if the meaning of a statement is positive, it is considered unacceptable to use two negatives to emphasize a negative meaning. In other words, it’s considered correct to say, “Tom was not unhappy with his divorce settlement,” since this statement has positive connotations (“Not” and “unhappy” are both negatives). Yet, it’s incorrect to say, “Tom does not have to answer to nobody,” because the statement does not have positive connotations (“Not” and “nobody” are both negatives.) One should instead say, “Tom does not have to answer to anybody.”
Use pronouns that agree with their antecedents in person and in number. Therefore, you should not use a singular pronoun to refer to a plural noun, nor should you use a plural pronoun to refer to a singular noun. For example, you should not say, “The company where I work treats their employees poorly” because “company” is third-person singular, and “their” is third-person plural. Instead, you should say, “The company where I work treats its employees poorly.”
In addition, watch out for constructions wherein you are using the correlative conjunctions “neither\\nor,” “not only\\but also” and “either\\or.” For example, you should not say, “Neither Tom nor Frank will share their sandwich,” but instead say, “Neither Tom nor Frank will share his sandwich.” After all, it’s highly unlikely the two men are eating the same sandwich.
Listen to how you sound. Pay attention to how you sound when speaking not only in professional settings but also informal settings. Consider purchasing a tape recorder and recording yourself speaking. Listen not only to your enunciation and word choice but also verb and pronoun usage. Perhaps even consider asking friends to allow you to tape conversations when you’re sitting around, relaxing and chatting, so you can hear how you sound when you’re not making a concerted effort to speak correctly.
Study the rules of grammar. According to Martha Kolln, author of “Understanding English Grammar,” the rules of grammar are defined as the “subconscious, internal system that enables us to generate grammatical sentences.\" Moreover, the rules that govern grammar are the “linguistic etiquette” or “the manners” of a language. Therefore, if you wish to exhibit linguistic etiquette and appear “mannerly” to your listeners, you must be able to speak using correct grammar. Yet, in order to speak correctly, you must first learn the rules, but you cannot learn those rules without making an effort, so you might consider taking a grammar course at school or online.