Are you writing follow-up with a hyphen between follow and up because that is how you have seen it written most often, so hopefully that is correct? But did you wonder why you also see follow up without the hyphen? Maybe that is correct? The answer is that both can be correct. It depends on the context in which the phrase is being used. This podcast explains when to use hyphens between two words that are normally separate.
This podcast explains where (and why) to use the past or the present tense (or the present perfect tense) of verbs in each part of a research paper. For example, should the Results section always be in the past tense? Which verb tense is correct for Figure Legends or Subheadings? Did you know that verb tenses can change within the same sentence? Even native-English authors of medical and science papers get the answers to these questions wrong!中文
When do you use indefinite articles, and which one do you use? There are two indefinite articles in English: “a” and “an.” The word indefinite as related to grammar means something that has not been identified, is generic, or is an unfamiliar person or thing. You use an indefinite article when (1) you are introducing new information, (2) the reader does not know exactly which noun you are referring to, or (3) the noun is not unique.中文