Each of the three lines may contain one of the following expressions:

Word
You can use two types of wildcard characters:

_ For a single character.
Es.: fatt_ = fatto, fatti, etc.
E.g.: fatt___ = fattore, fattori, etc.
E.g.: fatt____ = fattoria, fattorie, etc.
% For a single word.
E.g.: credo % che = credo proprio che, credo quasi che, etc.

The accented vowels have been reduced to vowel+apostrophe and should be searched for with vowel+backslash+apostrophe.

E.g.: cioe\' = cioè


Word class
Put a dot in front of the word class.
E.g.: .V = verb; .Av = adverb

Word class+lemma
.word class.lemma
E.g.: .V.fare = lemma "fare" as verb; .S.fatto = lemma "fatto" as noun

Word class+lemma+form
.word class.LEMMA.form
E.g.: .S.FATTO.fatti = lemma "fatto" as noun, form "fatti"; .V.FARE.fatto = lemma "fare" as verb, form "fatto".

Symbol or notation
E.g.: # = search for all pauses; $ = search for all positions in which a single unintelligible word occurs.

Group of tags
Put 5 dots (.....) in front of the expression.
E.g.: .....situazionali = search for all positions in which situational tags occur; .....turni/interlocutori = search for all positions in which turn-taking phenomena occur.

Single tag
Put 6 dots (......) in front of the expression and enclose it within square brackets.
E.g.: ......[applausi] = search for all positions in which the tag "applausi" occurs; ......[interiezione] = search for all positions in which the tag "interiezione" occurs.

Summing up, in every line you can type:
word (with wildcard character)
.word class
.word class.lemma
.word class.LEMMA.form
symbol
.....group of tags
......[tag]

You can directly type in the search string or let a help function do it for you.