It refers to the raise or fall of voice.

In an interrogative sentence, the intonation towards the end is...

In a declarative sentence, the intonation towards the end is...

In the sample (may, can, must), the meaning of each modals are:

It is the study how space is used in human interactions.

It is the study of time.

According to Edward Hall, Social space is from...

In a job interview, it is advised to wear...

When we talk of relationships, relationships are:

It includes handshake, holding hands, kissing, gentle pat on back, or a high five etc.

When it comes to non verbal communication meaning could change over different cultures.

It refers to breaks or pauses in speech that indicate words or other grammatical units.

It is the use of voice to communicate includes elements such as pitch, rate, pauses, volume, tone of voice, silences, laughs, screams, sighs, etc.

Ahs, ahms, ohhss, or other words/sounds we use when we are thinking of words/ thoughts to express.