counter suffix 助数詞のルール
one dog …いっぴきの犬
two dogs…にひきの犬

You may get confused about the counter suffix in Japanese.
Basically the counter suffixes are determined by shapes. And sometimes, you need to sound the number with ‘chocking sound’ irregularly, 1,6,8 and 10 are adopted.
Here helps you understand more about the regular/ irregular rules.
枚(Mai)… slice of…
Mai is used for the flat stuff like paper, pizza, T-shirt etc. You can simply add a number before the suffix.
2枚 にまいの紙
3枚 さんまいのTシャツ
4枚 よんまいのピザ
台(Dai)… for the equipment
Dai is used for the equipment like TV, bicycle, PC etc. It is also there’s nothing irregular rules.
5台 ごだいのテレビ
6台 ろくだいの自転車
7台 ななだいのパソコン
irregular ‘H’ suffixes
匹(Hiki, Biki, Piki) …for the small animals
Hiki is used for the small animals like dog, cat, mice etc. You need to sound the number with ‘chocking sound’ irregularly, 1,6,8 and 10 are adopted.
1匹の犬 いっぴきのいぬ
3匹の猫 さんびきのねこ
6匹のネズミ ろっぴきのネズミ
8匹のハムスター はっぴきのハムスター
Like above, the counter suffix starts with H sounds irregularly changes.
本(Hon, bon,pon) for the long stuff like banana, umbrella, pencil etc
杯(Hai, bai,pai) cup of,,, glass of,,, like wine , coffee, ramen, udon etc
Here are the rules for H sounds
e.g.) 匹 H=hiki B=biki P=piki
1 P 1杯:いっぱいの コーヒー ….. 1 needs a ‘chocking sound’
2 H 2本:にほんの かさ
3 B 3本:さんぼんの えんぴつ
4 H 4匹:よんひきの ねこ
5 H 5杯: ごはいの ワイン
6 P 6杯:ろっぱいの ラーメン …..6 needs a ‘chocking sound’
7 H 7匹:ななひきの ネズミ
8 P 8杯:はっぱいの ビール …..8 needs a ‘chocking sound’
9 H 9本:きゅうほんの バナナ
10 P 10本:じゅっぽんの ペン …..10 needs a ‘chocking sound’
( in Elementary school, it called じっぽん in national language lesson)
Can you say this?
1 dog ate 6 bananas , 8 carrots and 10 cucumbers!
↓
いっぴきの犬が、ろっぽんのバナナと、はっぽんのにんじんと じゅっぽんのきゅうりを たべた。

