Queries about English pronunciation

For both 'th' sound, you need to put your tongue tip between the upper teeth and the lower teeth. For 'th' in that, you dont need to breathe hard to produce the sound. For 'th' in through, you DO need to breathe air through the tongue-tip-between-upper-and-lower-teeth structure. This will give you the sound like 'f' but with the beginning of 'th'.

'sion' and 'tion' sound very similar. But for 'sion', you will need to make it sounds as if it starts with 'Z'.

that的th音較through的th音不吐氣
sion和tion的發音基本上是沒有分別的，如果興趣研究兩者的不同處請e-mail我。