by Emily Herring, Harvard College Writing Center English Grammar and Language Tutor
| #1: ARTICLES (the/a) I found a cat. = I found any cat. I found the cat. = I found a specific cat. I found cats. = I found a general group of cats. General rule: Use “a” for an unknown object; “the” for a specific, previously discussed object; and no article for an abstract object or general concept. |
| #2: APOSTROPHES I found the student’s book. = I found a book that belongs to one student. I found the students’ book. = I found a book that belongs to many students. I found the students’. = INCORRECT General rule: Use ’s to indicate one person’s possession of an object and s’ to indicate a group’s possession of an object. *The use of an apostrophe to indicate a plural is becoming widespread on social media platforms but is incorrect* |
#3: SUBJECT-VERB AGREEMENT The repairs that are occurring on the metro prevent a large portion of the population from accessing the city. General rule: Make sure that the proper verb form (“prevent”) accompanies the subject of the sentence (“repairs”). |
#4: PASSIVE VOICE The report was written by scientists. > The scientists wrote the report. The presentation was given by the student. > The student gave the presentation. General rule: While passive voice is not grammatically incorrect, it is better to use active voice to make your prose clearer and shorter! |
#5 PAST TENSE I lived in Boston for 3 years. > I no longer live in Boston. I have lived in Boston for 3 years. > I still live in Boston. General rule: Consider the time frame in which you are writing. The second example is more appropriate if you are writing in the present tense. |
The Barker Underground 