We'll look in more detail at noun clauses. We have already noted that certain verbs are followed by a noun clause are introduced in the present tense by bod and in the perfect tense by bod wedi for example:
Dw i'n gwybod bod y gêm yn dechrau am dri o'r glochI know that the game starts at three o'clockDw i'n meddwl eu bod nhw wedi gwahanuI think that they have separated.
However when noun clauses introduce future, long and short forms, future perfect and conditional tenses the noun clause is linked to the main clause by y or in front of a vowel yr. For example:
Dw i'n meddwl y bydda i'n hwyr I think that I'll be late
Mae e'n dweud y basai e'n gallu mynd He says that he would be able to go
Wyt ti meddwl y bydd e wedi gorffen? Do you think he will have finished?
Maen nhw'n dweud y daw o They say that he's coming
Mae'n siwr yr atebith hi'r llythyr I'm sure that she'll answer the letter
Rydyn ni'n meddwl yr aiff e We think that he'll go
Negative noun clauses are introduced by na or nad followed by the usual verb form.
Dw i'n siwr nad ydy o'n cofio I'm sure that he doesn't remember
Mae e'n meddwl na fydd e yno He doesn't think that he'll be there
All emphatic noun clauses are introduced by mai or in South Wales taw
Dw i'n siwr mai nhw fydd yn ennill I'm sure that they will win
Dw i'n siŵr na fyddan nhw'n cofio I'm sure that they will not remember
Here are some more common phrases that are followed by noun clauses
Mae'n rhaid Mae'n rhaid dy fod ti'n gwybod
You must know
Mae'n amlwg Mae'n amlwg ei bod hi'n cofio - It's obvious that she remembers
Mae'n annhebygol Mae'n annhebygol y bydd hi'n bwrw - It's unlikely that it will be raining
