The Major Scale is one of the most common types of scales. The organization of whole tones and semitones in an ascending scale are in the following order:

Tone, tone, semitone, tone, tone, tone semitone. 

This pattern will be in reverse when descending.

Listen to this major scale and then repeat the recording to sing along. Notice where the tones and semitones fall.

T = Tone (Whole Tone/2 semitones)

ST = Semitone