This tests adding prefixes to words. When you add re- to read, you get reread. Re- means to do something again.

This tests finding base words. The base word in painter is paint. The -er shows it's a person who paints.

This tests finding base words. The base word in helped is help. The -ed is the suffix at the end.

We are making new words with prefixes. When we add 're' to 'tell', we get 'retell'. Retell means to tell something again.

This question tests 2nd grade ability to decode words with prefixes and suffixes (CCSS.RF.2.3.d). Prefixes are word parts added to the beginning; suffixes are word parts added to the end. The suffix -ing means happening now or an ongoing action. When you add it to a base word like jump, which means to leap up, jumping means the action is happening right now. Choice A is correct because -ing indicates present or ongoing action, added to the end of jump. Choice B is incorrect because it describes -ed for past actions; this happens when students mix up tense-changing suffixes. To help students, use word building with tiles like jump + ing = jumping, and make charts showing -ing = happening now with examples like run to running. Use actions in real time with pictures, and watch for spelling changes like drop the e in jumping or doubling letters in running.

This question tests 2nd grade ability to decode words with prefixes and suffixes (CCSS.RF.2.3.d). Prefixes are word parts added to the beginning; suffixes are word parts added to the end. The prefix re- means again or to do something a second time. When you add it to a base word like read, which means to look at and understand words, reread means to read again. Choice A is correct because re- means again, and in reread, re- is added to the beginning of read to change the meaning to repeating the action. Choice B is incorrect because it confuses re- with un-, which means not; this happens when students don't recognize the specific meaning of each prefix. To help students, teach prefix meanings with charts like re- = again, using examples with familiar words like do to redo, and practice visual breakdowns like [re] + [read] = reread. Use pictures showing before (first read) and after (read again), and watch for students treating irregular words as if they have prefixes.

This question tests 2nd grade ability to decode words with prefixes and suffixes (CCSS.RF.2.3.d). Prefixes are word parts added to the beginning; suffixes are word parts added to the end. The prefix re- means 'again.' When you add it to a base word, it changes the meaning: play means to do an activity for fun, so replay means to play again. Choice B is correct because re- means again in replay, with the base word play and re- added to the beginning, together meaning to play again. Choice A is incorrect because it confuses re- with un-, which means not; this error happens when students mix up prefix meanings. To help students: Use visual breakdowns with color coding ([re] + [play] = replay). Teach prefix meanings explicitly (re- = again, un- = not). Start with familiar base words (play, do). Practice covering up the prefix to reveal the base word. Make word family charts showing base word + different prefixes. Use pictures to show before/after (play → replay). Watch for: confusion between similar prefixes like re- and pre-.

We are finding base words. The base word is the main word without prefixes or suffixes. In unlock, the base word is lock.

We are learning about suffixes. The suffix -less means without something. When you are careless, you are without care.

We're learning about suffixes. The suffix '-ed' tells us something happened before. When we add -ed to play, it means we played already.