Pe bawn i...: bawn is a conditional form of the verb bod and means 'if I were to …'
Pe baswn i is also another commonly used form which also means 'if I were to …'

When using pe bawn i... in a sentence, it is followed by a clause which also uses the conditional tense, e.g.

Pe bawn i'n graddio'n dda, byddwn i'n cael parti mawr.

• Pe bawn i (I)
• Pe baet ti (you)
• Pe bai e/o (he)
• Pe bai hi (she)
• Pe baen ni (we)
• Pe baech chi (You)
• Pe baen nhw (They)

When using negative forms of the conditional tense bod, the b takes a soft mutation and is replaced with a f and ddim is also added, e.g.

Pe bawn i'n graddio, fyddwn i ddim yn darllen llyfr arall am fis.

Positive	Negative
Byddwn i	Fyddwn i ddim
Byddet ti	Fyddet ti ddim
Byddai e/o	Fyddai e/o ddim
Byddai hi	Fyddai hi ddim
Bydden ni	Fydden ni ddim
Byddech chi	Fyddech chi ddim
Bydden nhw	Fydden nhw ddim

Take care not to mix these tenses with the future tense

Bydda i	I will
Byddi di	You will
Bydd e/o	He will
Bydd hi	She will
Byddwn ni	We will
Byddwch chi	You will
Byddan nhw	They will