Parallel structure refers to sentences that express one or more similar ideas using the same pattern of words. The ideas are normally joined using conjunctions, such as "and" or "or." An example of parallel structure is, "Mary likes swimming, hiking and riding" because of the use of grammatically equal "-ing" form of words. "Mary likes swimming, hiking and to ride bikes" is not a parallel sentence because "ride" does not use the "-ing" ending that "swimming" and "hiking" do.

When learning English for the first time it is important for students to realize the importance of parallel structure within the language. Native English speakers are rarely aware that they use parallel structures but for non-English speakers the concept of using parallel sentencing can be difficult to grasp. English as a Second Language (ESL) students should be encouraged to explore parallel sentence structures through activities and oral communication rather than textbook lessons.

Identifying Parallel Structure
Provide students with a basic overview of parallel structure in sentences, either spoken or written. When students are familiar with the basic concept of parallel sentences, you can then provide them with a list of sentences, some of which are parallel and some of which are not. Have students identify which sentences are parallel structure and read parallel-structure sentences to the class, as well as briefly explain why they are parallel or how they identified the sentence as parallel structure.

Creating Parallel Structure
Give students a simple sentence with blank spaces in it, such as "John asked to borrow blank, blank and blank." Have students fill in the blank spaces to make the sentence parallel, either from a list of words or from any other words they can think of. Words listed in the blank spaces must be of equal grammatical structure.

Students can also perform the task of filling in the blank spaces with the aim of creating a sentence that is not parallel, or by creating one parallel sentence from the blanks and one non-parallel sentence from the same question.

Parallel Sentence Correction
Give students sentences that deliberately are not parallel but that can easily be modified to create parallel sentence structures. For example, a sentence such as "For her birthday, Mary received a CD player, some clothes and got a cake" can be modified be students to show a parallel structure. Students can then read their modified sentences to the class and ask for feedback from other students or from the tutor to establish whether their modified sentences are grammatically correct.

Card Exercise
Split the class into groups. Provide each group with a sentence and cards with different words on them--for example, jogs, jogging, rides, riding. Ask students to replace one word in the sentence provided with a word from their cards to create parallel sentence structure. Then ask them to read their sentences to the class, explaining which word they replaced and why the new sentence is parallel.

You can also leave the cards in the middle of the classroom, so that groups must select words from a larger assortment of cards and can collaborate with other students.