Sentence improvement (verb form of lie and lay): choose the best substitute for the underlined part in the sentence below. Poor Tom laid in the shade of a tree before he could walk further.

Introduction / Context:
This question checks your understanding of the confusing verb pair \"lie\" and \"lay\". Many learners mix up these forms because they sound similar and both relate to positions or movement. Here, the sentence describes Tom resting in the shade, so the correct intransitive verb form is required.

Given Data / Assumptions:

• Original sentence: Poor Tom laid in the shade of a tree before he could walk further.
• The meaning is that Tom rested or reclined under the tree.
• Options: lied, lain, lay, no improvement.
• No object follows the verb, so it must be an intransitive form of \"to lie\" (to recline).

Concept / Approach:
There are two different verbs to remember:

• \"lie\" (lie, lay, lain, lying) meaning \"to recline\" and intransitive.
• \"lay\" (lay, laid, laid, laying) meaning \"to put or place something\" and transitive.

In the sentence, Tom is not putting anything down; he himself is in the reclining position. Therefore, the past tense of \"lie\" is required, which is \"lay\". The given \"laid\" is the past tense of \"lay\" (to put something), which is incorrect here.

Step-by-Step Solution:
Step 1: Identify the intended meaning: Tom was resting or lying under the tree. Step 2: Recognise that the verb is intransitive because there is no direct object after it. Step 3: Select the correct verb \"lie\" (to recline). Its past tense form is \"lay\". Step 4: Replace \"laid\" with \"lay\" to get \"Poor Tom lay in the shade of a tree.\" Step 5: Verify that all other options do not fit the tense and structure correctly.

Verification / Alternative check:
A useful pattern to memorise is:

• Today I lie down; yesterday I lay down; I have often lain down.
• Today I lay the book on the table; yesterday I laid the book on the table; I have often laid the book on the table.

Applying this to the sentence shows that \"Tom lay\" (past of lie) is the correct form. \"Tom laid\" would require an object such as \"Tom laid the bag on the ground\", which is not present here.

Why Other Options Are Wrong:
Option \"lied\": This is the past tense of \"lie\" meaning \"to tell an untruth\", not \"to recline\". It changes the meaning completely. Option \"lain\": This is the past participle of \"lie\" and would need an auxiliary verb, such as \"had lain\" or \"has lain\". It cannot stand alone here. Option \"no improvement\": Keeping \"laid\" would keep the incorrect transitive form in place.

Common Pitfalls:
Confusing \"lay\" and \"lie\" is very common. Learners often assume that \"laid\" is always correct in the past. Remember to ask yourself whether the verb takes an object. If there is no object and the subject is simply resting, the correct verb is \"lie\" with past tense \"lay\".

Final Answer:
The sentence should read: Poor Tom lay in the shade of a tree before he could walk further. Therefore, the correct option is lay.