Quick answer
Т т is the t of “top”, unaspirated, with the tongue against the teeth. In cursive, lowercase т is written like a Latin m.
t
How to say it
An English t without the breath, and further forward in the mouth. Before и, е, ё, ю, я it softens: тип sounds closer to “tyeep”.
The -ть ending
Nearly every Russian infinitive ends in -ть: быть, чита́ть, говори́ть, люби́ть. The soft sign makes the т soft, which is why the ending sounds like a short “tj” rather than a hard t. Spotting -ть is the fastest way to recognise a verb in its dictionary form.
The cursive problem
Handwritten т is a three-humped shape identical to a Latin m, and handwritten м is something else again. The word тот written by hand reads convincingly as “mom”. This is the single biggest obstacle to reading Russian handwriting.
Typical mistakes
Aspirating the т in там
no puff of air
Russian stops are unaspirated.
Reading handwritten т as m
It is т
Cursive т takes the shape of a Latin m.
Check yourself
Which word contains Т?