Whereas a slur connects notes of different pitches, a tie is a curved line which connects two notes with the same pitch. They can be of equal length or not. The tie tells you to tongue the first note only, and to hold it for the length of both notes.
Play the G note and hold it for six beats.
A tie may occur either across a bar line, or within one bar. The following melody contains examples of both. Remember not to confuse the tie with the slur, which connects notes of different pitches.
To finish this section, here are two more examples which make use of everything you have learned up to this point. To help you develop a good sense of time, try tapping your foot as you play. Also, remember to keep counting regardless of whether you see notes, rests or ties in the written music.