Too, easy, hard
Suffixes on the verb stem that grade how something goes: too much, easy, hard, and the way to do it.
-sugiru
polite -sugimasutoo much, over-
〜すぎる 〜すぎます
Attaches to a verb stem or adjective stem for overdoing or excess (tabesugita, takasugiru, shizukasugi), and the bare -sugi is common in reactions.
kinou chotto nomisugita.
I drank a bit too much last night.
昨日ちょっと飲みすぎた。
kinou chotto nomisugimashita.
I drank a bit too much last night.
昨日ちょっと飲みすぎました。
Casual reactions use bare -sugi to mean 'so X', not 'too X': oishisugi = so good, kawaisugi = so cute (youth slang; keep it among friends).
-yasui
polite -yasui desueasy to
〜やすい 〜やすいです
Attaches to a verb stem for 'easy to' (wakariyasui, tsukaiyasui) or 'prone to' (tsukareyasui), and conjugates like an i-adjective.
kono pen, kakiyasui.
This pen is easy to write with.
このペン、書きやすい。
kono pen, kakiyasui desu.
This pen is easy to write with.
このペン、書きやすいです。
Not 'cheap': after a verb stem yasui means easy.
Learn alongside: -nikui
-nikui
polite -nikui desuhard to
〜にくい 〜にくいです
Attaches to a verb stem for 'hard to' (kikinikui, tabenikui), a soft way to say something is awkward or inconvenient.
kono pen, kakinikui.
This pen is hard to write with.
このペン、書きにくい。
kono pen, kakinikui desu.
This pen is hard to write with.
このペン、書きにくいです。
iinikui n da kedo (this is hard to say, but...) is a common lead-in to awkward news.
-kata
way of -ing
〜方 〜かた
Attaches to a verb stem to make a noun meaning the way to do it (tsukaikata, yarikata, iikata), which covers 'how do you...?' without new grammar.
kore no tsukaikata wakaru?
Do you know how to use this?
これの使い方分かる？
kore no tsukaikata wakarimasu ka?
Do you know how to use this?
これの使い方分かりますか？
The object takes no: kanji no kakikata (*kanji o kakikata). Suru nouns take no shikata: benkyou no shikata.