Sentence Detective

Overview

Across three 15-minute lessons, students identify and distinguish declarative (statement) and interrogative (question) sentences. They will notice each sentence’s purpose, use correct capitalization and ending punctuation, and explain their choices in complete sentences.

Learning intentions

• Students will be able to identify declarative and interrogative sentences.
• Students will be able to explain that declarative sentences tell something and interrogative sentences ask something.
• Students will be able to capitalize the first word of a sentence and use a period or question mark correctly.
• Students will be able to write and discuss complete sentences.

Success criteria

• I can tell whether a sentence is a statement or a question.
• I can explain what a declarative or interrogative sentence does.
• I can use a capital letter at the beginning of a sentence.
• I can use a period for a statement and a question mark for a question.

Curriculum links

• Produce simple, compound, and complex sentences.
• Explain the function of nouns, pronouns, verbs, adjectives, and adverbs in particular sentences.
• Engage effectively in collaborative discussions with diverse partners.
• Speak in complete sentences to provide requested detail or clarification.

Lesson structure (3 days, 15 minutes per day)

Day 1: Identify the sentence purpose

1. 0–3 min · I Do—Hook and model. Display “The dog is sleeping.” and “Is the dog sleeping?” using the sentence detective introduction slides. Read both aloud, think aloud about the different purposes, and model a capital letter, period, and question mark. Students listen and show a silent thumbs-up when they hear a sentence that tells something.

2. 3–7 min · I Do—Teach the terms. Explain that a declarative sentence tells or states something and ends with a period; an interrogative sentence asks something and ends with a question mark. Students repeat each term and punctuation mark, then say the purpose of each sentence in a complete sentence.

3. 7–12 min · We Do—Class sort. Reveal four sentences in the deck, including “Birds build nests.” and “Where do birds build nests?” Teacher reads each sentence and invites students to identify its type and punctuation. Students discuss answers with a partner, then share using “I think it is ___ because ___.”

4. 12–15 min · You Do—Quick check. Distribute the three-day sentence detective worksheet and have students complete Day 1 by labeling two sentences D or I and adding the correct ending mark. Collect or quickly scan responses.

Day 2: Correct capitalization and punctuation

1. 0–3 min · I Do—Review and model. Revisit the sentence types with the review and editing slides. Model correcting “where is my book” to “Where is my book?” and explain that the first word begins with a capital letter and the question ends with a question mark. Students identify the two corrections.

2. 3–7 min · We Do—Edit together. Display three sentences with missing capitals and punctuation. Teacher guides students to read each sentence, decide whether it tells or asks, and correct it. Students explain their choices to a partner using complete sentences.

3. 7–12 min · You Do—Independent practice. Students complete the Day 2 section of the three-day sentence detective worksheet, correcting capitalization and punctuation in four sentences and labeling each as declarative or interrogative. Teacher conferences briefly with students who need support.

4. 12–15 min · We Do—Check and explain. Review answers with the class. Students hold up one finger for declarative or two fingers for interrogative, then explain one answer using “It is ___ because it ___.”

Day 3: Apply and demonstrate understanding

1. 0–3 min · I Do—Model writing. Use the writing and exit-ticket slides to model turning a picture prompt into one statement and one question: “The girl reads a book.” and “What is the girl reading?” Students identify the purpose and punctuation in each example.

2. 3–7 min · We Do—Build sentences. Work with the class to create one declarative and one interrogative sentence about a familiar classroom object. Teacher records student ideas, prompting for a complete thought, a capital letter, and the correct ending mark. Students rehearse both sentences with a partner.

3. 7–12 min · You Do—Independent application. Students complete the Day 3 section of the three-day sentence detective worksheet by writing one declarative sentence and one interrogative sentence about a classroom or animal picture, then labeling each sentence. Teacher checks for meaning, capitalization, and punctuation.

4. 12–15 min · We Do—Share and exit ticket. Invite two or three students to read a sentence aloud. Students complete the final exit ticket on the worksheet: correct “can you find the red crayon” and write whether it is declarative or interrogative. They explain their answer in one complete sentence before turning it in.

Resources

• the three-day sentence detective slide deck
• the three-day sentence detective worksheet
• Whiteboard and marker
• Pencils
• Four sentence examples for display
• Classroom or animal picture prompts
• Document camera or display screen

Assessment

• Listen during partner discussions for accurate use of declarative and interrogative and complete explanations.
• Check students’ finger signals, sentence sorting, and editing responses during teacher-led practice.
• Use the Day 3 exit ticket to assess sentence type, capitalization, punctuation, and ability to explain the choice.

Differentiation

• Provide sentence frames: “This is a ___ sentence because it ___.” and “I wrote ___ because ___.”
• For students needing support, read sentences aloud, use color coding for the capital letter and ending mark, and offer a word bank with tells, asks, period, and question mark.
• Pair students strategically and allow students to rehearse answers orally before writing; provide enlarged text or a scribe as needed.
• For advanced learners, ask them to write two different questions about the same picture and explain how changing the punctuation or wording changes the sentence’s purpose.