One of the most common mistakes we see in ESL students’ writing concerns doubling the last letter of a verb when we add “-ing” or “-ed” to it. ESL students do not know when to double it and when not to. In students’ essays, I often see spelling mistakes like this: “planing” for “plan,” “rainning” for ”rain,” “writting” for “write,” ”enjoyying” for “enjoy,” “studing” for “study,” “prefering” for “prefer,” and “offerring” for “offer.” These mistakes show that the students have not fully understood the grammatical rules used here.
Actually, the rule is not simple. We often give our students an incomplete rule. Here are a few things we need to do. First we should help students understand SYLLABLES. They need to be able to make a distinction between one-syllable verbs and two-syllable verbs. If a one-syllable verb ends with a single vowel letter + a single consonant letter, then we need to double the consonant letter before adding “-ing”. For example, “hitting”, but “eating”. We do not double “t” in “eating” because there are two vowel letters. For two-syllable verbs, what makes the difference is the stress. If the stress is on the first syllable, we’ll never double the last consonant letter; if the stress is on the second syllable, then we need to follow the rules to double or not to double the last consonant letter. That is why it is “referring”, but “offering”. -Ron Lee