In the following sentence, a blank is given which must be filled with the most appropriate verb form. Select the correct alternative out of the four given options. He _____ his camera on the table.

Introduction / Context:
This question tests your understanding of commonly confused verb forms, particularly the verbs lay and lie. Many learners mix up these verbs because their forms look similar. The sentence describes an action of putting an object, namely a camera, on a table. You need to select the correct past tense form that matches this action.

Given Data / Assumptions:
- Sentence: He _____ his camera on the table. - Options: laid, lain, lay, lie. - The sentence clearly refers to past time and involves an object, the camera, which is being placed somewhere.

Concept / Approach:
The key is to remember that lay is a transitive verb, which means it takes a direct object, and its past tense is laid. The base form lie, meaning to recline, is intransitive and does not take a direct object, and its past tense is lay and past participle is lain. Because the sentence has a direct object, his camera, we must choose a form of lay in the sense of put or place. Among the options, laid is the correct past tense of this transitive verb.

Step-by-Step Solution:
Step 1: Identify that his camera is the object of the verb, so the verb must be transitive. Step 2: Recall that lay (to put or place something) takes an object and has the forms lay, laid, laid. Step 3: Recall that lie (to recline) does not take an object and has the forms lie, lay, lain. Step 4: Since the sentence is in simple past and involves placing the camera on the table, we need the past tense of lay in the transitive sense, which is laid. Step 5: Therefore, He laid his camera on the table is the correct sentence.

Verification / Alternative check:
Test each option in the sentence. He laid his camera on the table is natural and correct. He lain his camera on the table is wrong because lain is a past participle of lie and is not used with a direct object in this way. He lay his camera on the table sounds wrong because lay as past tense of lie does not take an object, and in standard English we use laid when an object is present. He lie his camera on the table is incorrect because lie is the base form and does not match the past time reference.

Why Other Options Are Wrong:
Lain is wrong because it is the past participle of lie in the sense of recline and is used with have or had, not directly with an object. Lay is wrong here because the simple past of lay in the transitive sense is laid, and lay would be interpreted as past of lie, which does not fit a direct object. Lie is wrong because it is present tense and intransitive, unsuitable for a sentence that clearly refers to a past completed action involving an object.

Common Pitfalls:
Many learners confuse lay and lie because speakers sometimes use lay instead of lie in casual speech. Examination questions often test this area to check precise knowledge. To avoid confusion, remember the simple pattern: lay, laid, laid (always with an object) and lie, lay, lain (no direct object). Practice making small example sentences such as I lay the book on the table and Yesterday I laid the book on the table. These patterns will help you remember the correct forms during the exam.

Final Answer:
The correct sentence is: He laid his camera on the table.