Learn English – How is the phrase ‘as…as’ used

"Better sooner than later" is already an abbreviation of the full phrase, so it's more common to use it in an abbreviated sentence where the context is already known:

I told him better sooner than later.

Otherwise if you have to explain the context, it's more natural to include more detail:

I told him, if you're going to send that letter, then sooner is better than later.

If you're going to send that letter, better send it sooner rather than later.

There are many variations of this phrase, and I wouldn't consider this a formal rule. It's fine either way.

Let's contemplate:

1. "In particular" is an idiomatic expression that means "in distinction from others" or "specifically". This expression usually refers to nouns and is set apart by a comma when it occurs at the beginning of a sentence or a phrase.
2. "Particularly" means "in detail" or "to an unusual degree". It is an adverb, and as such it can be used to modify a verb, an adjective, or another adverb but not nouns. It is not set off by a comma from the rest of the sentence.

Both uses of particular have the same meaning, but are used in different ways. We could also say in specific and specifically (which is more formal but has the same meaning). ELB - English Lessons Brighton.

Often, particularly can also be used as an adverb in place of in particular to specify something individually. But in this case it is used relative to earlier details. Examples below have the same meaning:

• The weather was bad this week, particularly on Wednesday.
• The weather was bad this week, on Wednesday in particular.

Here, used in a relative clause (one that works relating to the main clause), particularly means specifically or especially, and is essentially the same as in particular. But if we used it in the main clause, the meanings of the two phrases would differ:

• The weather was particularly bad this week. (The weather was worse than usual.)
• In particular, the weather was bad this week. (The weather was one thing that was specifically bad, amongst other things.)

Note, though, that in particular can never be used in place of particularly to modify verbs.

Summing up, yes, we can use both words in a sentence:

• In particular, disease A is considered particularly contagious. (Specifically, disease A is considered highly (unusually) contagious.)

Extra Info: "Considered" and "Considered to be" are interchangeable, however, "To be" is redundant)*. You can also say, "Considered as being"