Is using split infinitive allowed in formal English? [duplicate]

Question

Possible Duplicate:
Are split infinitives grammatically incorrect, or are they valid constructs?

Is it allowed to use split infinitives in formal English? I look into Wikipedia but it is too objective and it doesn't directly say that I can use it formally. Is split infinitives grammatical?

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from Wikipedia:

A split infinitive is an English-language grammatical construction in which a word or phrase, usually an adverb or adverbial phrase, comes between the marker to and the bare infinitive (uninflected) form of a verb.

In some cases, moving the adverbial creates an ungrammatical sentence or changes the meaning. R.L. Trask uses this example:

• She decided to gradually get rid of the teddy bears she had collected.
  "Gradually" splits the infinitive "to get". However, if the adverb were moved, where could it go?

• She decided gradually to get rid of the teddy bears she had collected.
  This might imply that the decision was gradual.

• She decided to get rid of the teddy bears she had collected gradually.
  This implies that the collecting process was gradual.

• She decided to get gradually rid of the teddy bears she had collected.
  This sounds awkward, as it splits the phrase "get rid of".

• She decided to get rid gradually of the teddy bears she had collected.
  This is almost as unwieldy as its immediate predecessor.

Answer 1

It is perfectly fine as long as it isn't awkward, uncomfortable usage. As those examples point out, using split infinitives is often the only way of conveying your message accurately, and this criterion trumps everything else.

It should be acceptable for formal writing and you can confirm this to an extent by sifting through Google Books or a suitable corpus.