An interlocutor is the person(s) to whom speech is directed (for example if a boy is talking to a girl the girl is the interlocutor). In many Romance languages, the subject(s) who is/are talking is/are the locutor(s). The use of the word 'locutor,' however, is not yet formally correct in the English language. Grammatically, an interlocutor is when the object of that speech is also named in the phrase (the name or title of the interlocutor is stated in the sentence).

• Hello Phill how are you?

Phill is the interlocutor (the speaker is directing his/her speech towards him) and his name (or title) is also stated in the sentence.

The interlocutor is almost always an object but may be the subject. which refers to the recipient of a dialogue in which their name (or title, or other labels) is mentioned in the phrase. The following sentence does the same but with the use of a title instead of a proper name.

• Mrs. Fickleby, can I go to the washroom?

In this sentence the interlocutor is a classroom teacher (Mrs. Fickleby). In most Romance languages, the student (addressing the teacher) would be called the 'locutor.' Essentially in this case and most cases, Mrs. Fickleby is the interlocutor because her name (or title, etc...) was mentioned in the speech directed towards her. If the student simply asked to go to the bathroom:

• Can I go to the washroom?

The sentence would no longer have an interlocutor [in the sense of the role of a word in the sentence] (even though the two sentences virtually mean the same thing) as the object (the teacher) in this case was not addressed by their name or other title.

The interlocutor may be addressed by his or her common name, title or by a structure unique to phrases with interlocutor as a part of speech.
Using an interlocutor in English is relatively easy compared to the use of an interlocutor in other languages. The structure of a sentence changes and there is no morphological change to the noun when an interlocutor. In some languages, using a locutor changes the meaning of the sentence in subtle ways. Its use in some languages involve changing the syntax (word order) or changing the noun when interlocutor such as the use of suffixes.

Varieties of interlocutors

The following examples include the interlocutor directly addressed in various ways, the interlocutor in italics.

• This isn't going to work John.
  • Interlocutor by name

• Hello Sir, how was your day?
  • Interlocutor by title

• My sweetie I missed you.
• Hey jerk I'm talking to you.
  • Interlocutor by name of affection or insult.

• We welcome you Our Most Esteemed Guest.
  • Interlocutor by honourific title.

• God save the King.
  • Interlocutor in subjunctive mood.

• John, my friend, you always get here late!
  • Interlocutor as both name and title.

• 'Mom' are you here?
  • Interlocutor as familiar name.

Interlocutors in English

The structure of an English sentence may change when using an interlocutor as opposed to sentences without the use of one. In English

English language

English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 the difference in sentence structure is either non-existent or small. In almost all sentences where an interlocutor is mentioned in the third person singular (extreme polite form) the subjunctive mode is used in English.

• We would be happy that our guest eat with us tonight.

Someone speaking to their guest in an extreme polite form. Notice that guests does not take the suffix -s as it would in a sentence describing what he does.

• Our guest eats with us when he likes.

If the interlocutor is titled twice in a phrase, there is a specific order that must be used. In the last example of the above list, name of object comes before title.

John, my friend, you always get here late!

Thus in this example, when both "John" and "Friend" are used in a sentence as the same object as the interloctur "John" comes before "My friend" (name before title). Notice the change in a sentence describing his friend.

• "My friend, John, always arrives late".

In some cases a sentence using an interlocutor and one without may appear the same however a comma will be used to clearly distinguish them in written form. Orally the intonation will be different. Notice the difference in writing and intonation of Sarah.

• I don't know Sarah.

This sentence does not have an interlocutor.

• I don't know, Sarah.

Here, Sarah is clearly the interlocutor.

The first sentence deals with the subject not familiar with someone named Sarah. The second, the 'locutor' informs Sarah, as interlocutor, that he or she does not know the answer to something. The intonation (varied depending on dialect/accent) is usually quite distinguishable oraly. The lack of comma in the first sentence and use of it in the second is not optional.

Interlocutors in other languages

In some languages, especially Slavic languages as well as other languages in the Indo-European family the use of an interlocutor may denote a sense of formality between the 'locutor' and object of the sentence (as in someone speaking to a stranger or one showing deference). Use of the interlocutor in such languages involves a noticeable change in the sentence structure and or morphology of the object as interlocutor (the object may take a suffix and/or affect another part of speech connected to it).

The following example shows the difference in Polish between a sentence with and without an interlocutor with the same subject/object, in this instance Chris (Krzys). Here, Chris takes the suffix iu when as an interlocutor.

• Kocham Krzysia. (I love Chris)

Chris is the object of the sentence but not the interlocutor.

• Kocham cię, Krzysiu! ("I love you, Chris!")

Chris is the interlocutor of the sentence and in this case takes the suffix iu clearly denoting him as the interlocutor. There is no equivalent in English.

In Portuguese

Portuguese language

Portuguese is a Romance language that arose in the medieval Kingdom of Galicia, nowadays Galicia and Northern Portugal. The southern part of the Kingdom of Galicia became independent as the County of Portugal in 1095...

 in various tenses different prepositions may be used depending on whether the object of a sentence is an interlocutor or not.

When suffixes are systematically added (or some morphological change to the subject occurs) the structure can be often expressed as the vocative case.