Final answer:
The correct way to complete the sentence in indirect speech is 'They said they would check the price online', shifting the future tense 'will' to 'would'.
Step-by-step explanation:
The sentence 'We'll check the price online' is in the future tense. If you want to report what they said using indirect speech, you need to change the tense to the past. Thus, the correct completion of the sentence 'They said they _____ the price online' using indirect speech is 'They said they would check the price online.'
This change from 'will' to 'would' is a common rule when you are reporting speech in English and changing the statement from direct to indirect speech.
"We'll check the price online." They said they would verify the price online. The transformation from the future tense to reported speech in the past involves changing the modal verb "will" to "would" to maintain grammatical consistency. In this context, it reflects their intention to verify the price on the internet.
Reported speech is a common way to convey what someone has said while adapting the tense and perspective to fit the context of the reporting.