underlie vs. underlay

[khanhhung2512]

We all know how frustrating it is to distinguish between "lie (lay, lain)" and "lay (laid, laid)". However, at least, one is transitive and one is intransitive. Now I just found out that "underlie (underlay, underlain)" and "underlay (underlaid, underlaid)" are both transitive verbs.
http://www.merriam-webster.com/dictionary/underlie
http://www.merriam-webster.com/dictionary/underlay
Would you help me to differentiate between 'underlay (v.)' and sense 2 & 3 of 'underlie', please?
Moreover, could you be so kind to help me with the two following questions please?

1) He plays rock music but ... with jazz, blues and soul.

	A. underlain
	B. underlaid

2) Some areas in the study region were ... by chalk or limestone.

	A. underlain
	B. underlaid

The answer to these questions is 1B 2A. What do you think about the answer key? Could you please explain it?
Thank you very much.

 

[Charlie Bernstein]

Ugh. I think you're the victim of poorly worded test questions.

The correct word for #1 is B. I would have put a comma after but. It's underlaid because it's a simple past-tense verb.

In #2, I don't understand the use of by. By can mean beside or next to, which doesn't make much sense. Or it can mean that the chalk and limestone did the laying, which makes even less sense. So in #2, as in #1, I would have said with, not by (like #1) and, again, used underlaid.

Sorry I can't be more help. But I will say this: Underlay is a very uncommon word, and no native English speaker will mind if you never use it (in any of its verb forms).

 

[khanhhung2512]

The correct word for #1 is B. I would have put a comma after but. It's underlaid because it's a simple past-tense verb.

Did you mean before but and past-participle?
"He plays rock music but underlaid with jazz, blues and soul." Well, I still think this sentence is fine without a comma preceding 'but'.

 

[Raymott]

"He plays rock music but underlaid with jazz, blues and soul." Well, I still think this sentence is fine without a comma preceding 'but'.

Yes, you are right. A comma could appear before, but not after, 'but'.